Abstract:
This invention refers to 7-amino mitosane analogs (mitomycin C) in which the 7-amino group bears an organic substituent incorporating a disulfide group and to a novel thiol exchange process for producing these compounds. The compounds are inhibitors of experimental animal tumors.

Description:
REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of application U.S. Ser. No. 581,291 filed Feb. 24, 1984 now Pat. No. 4,803,212 which in turn is a continuation-in-part of Ser. No. 484,016 filed Apr. 12, 1983, and now abandoned. The entire disclosure of U.S. Ser. No. 581,291 is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present compounds are mitomycin C analogs (Class 548, Subclass 422) in which the 7-amino group is substituted by a disulfide containing organic group. These compounds are inhibitors of experimental animal tumors. 
     BACKGROUND OF THE INVENTION 
     Nomenclature--The systematic Chemical Abstracts name for mitomycin C is (Shirahata et al., J. Am. Chem. Soc. 1983, 105, 7199-7200): 
     [1aS-(1aβ,8β,8aα,8β)]-6-amino-8-[(aminocarbonyl)oxy)methyl]-1,1a,2,8,8a,8b-hexahydo-8a-methoxy-5-methylarizidino[2&#39;,3&#39;,3,4,]pyrrolo[1,2-a]indole-4,7-dione according to which the azirinopyrroloindole ring system is numbered as follows: ##STR1## 
     A trivial system of nomenclature which has found wide use in the mitomycin literature identifies the foregoing ring system including several of the characteristic substituents of the mitomycins as mitosane. ##STR2## We have chosen in the present specification to use this system and to refer to the aziridino nitrogen atom as 1a and the ring amino nitrogen atom as 7-NH 2 . As to the stereochemical configuration of the products of this invention, it is intended when identifying them by the root name &#34;mitosane&#34; or by structural formula to identify the stereochemical configuration thereof as the same as that of mitomycin C. 
     DESCRIPTION OF THE PRIOR ART 
     Mitomycin C is an antibiotic which is produced by fermentation and is presently on sale under Food and Drug Administration approval for the therapy of disseminated adenocarcinoma of the stomach or pancreas in proven combinations with other approved chemotherapeutic agents and as palliative teatment when other modalities have failed (Mutamycin® Bristol Laboratories, Syracuse, N.Y. 13201, Physicians&#39; Desk Reference 35th Edition, 1981, pp. 717 and 718). Mitomycin C and its production by fermentation is the subject of U.S. Pat. No. 3,660,578 patented May 2, 1972 claiming priority from earlier applications including an application filed in Japan on Apr. 6, 1957. 
     The structures of mitomycins A, B, C, and of porfiromycin were first published by J. S. Webb et al. of Lederle Laboratories Division American Cyanamid Company, J. Amer. Chem. Soc. 84, 3185-3187 (1962). One of the chemical transformations used in this structure study to relate mitomycin A and mitomycin C was the conversion of the former, 7-9α-dimethoxymitosane, by reaction with ammonia to the latter, 7-amino-9α-methoxymitosane. Displacement of the 7-methoxy group of mitomycin A has proven to be a reaction of considerable interest in the preparation of antitumor active derivatives of mitomycin C. The following articles and patents deal with the conversion of mitomycin A to 7-substituted amino mitomycin C derivatives having antitumor activity. The object of this research was to prepare derivatives which were more active, and particularly which were less toxic than mitomycin C: 
     Matsui et al. The Journal of Antibiotics, XXI, 189-198 (1968). 
     Kinoshita et al. J. Med. Chem. 14, 103-109 (1971). 
     Iyengar et al. J. Med. Chem. 24, 975-981 (1981). 
     Iyengar, Sami, Remers, and Bradner, Abstracts of Papers 183rd Annual Meeting of the American Chemical Society, March 1982, No. MEDI 72. 
     Iyengar et al. J. Med. Chem. 1983, 26, 16-20. 
     Iyengar et al. Abstracts of Papers, 185th Annual Meeting of the American Chemical Society, March 1983, No. MEDI 82. 
     The following patents deal with the preparation of 7-substituted aminomitosane derivatives by the reaction of mitomycin A, mitomycin B, or an N 1a  -substituted derivative thereof with a primary or secondary amine: 
     Cosulich et al. U.S. Pat. No. 3,332,944 patented July 25, 1967. 
     Matsui et al. U.S. Pat. No. 3,420,846 patented Jan. 7, 1969. 
     Matsui et al. U.S. Pat. No. 3,450,705 patented June 17, 1969. 
     Matsui et al. U.S. Pat. No. 3,514,452 patented May 26, 1970. 
     Nakano et al. U.S. Pat. No. 4,231,936 patented Nov. 4, 1980. 
     Remers, U.S. Pat. No. 4,268,676 patented May 19, 1981. 
     Remers, Belg. No. 893,162 patented May 12, 1982. 
     Mitomycin C derivatives having a substituted amino substituent in the 7-position have also been prepared by directed biosynthesis, that is by supplementing fermentation broths with a series of primary amines, and carrying out the conventional mitomycin fermentation (C. A. Claridge et al. Abst. of the Annual Meeting of Amer. Soc. for Microbiology 1982. Abs. 028). 
     SUMMARY OF THE INVENTION 
     The present invention relates to a process for the preparation of the compounds claimed in U.S. Ser. No. 581,291 which are represented by Formula IX below. The process is depicted in the reaction scheme shown. ##STR3## 
     In Formula IX R 9  is an organic group, viz. the structural component of an organic thiol of the Formula R 9  SH. R and Alk 2  have the definitions given in U.S. Ser. No. 581,291 viz. R is hydrogen, lower alkyl, lower alkanoyl, benzoyl, or substituted benzoyl wherein said substituent is lower alkyl, lower alkoxy, halo, amino, or nitro. Alk 2  is a straight or branched chain alkylene group having 2 to 7 carbon atoms and optionally bearing an R 7  substituent wherein said R 7  is selected from the group consisting of hydroxy, halo, amino, alkylamino or dialkylamino having 1 to 12 atoms, alkanoylamino, benzoylamino or A-substituted benzoylamino, naphthoylamino or A-substituted naphthoylamino, cycloalkyl or A-substituted cycloalkyl each having 3 to 8 members, cycloalkenyl or A-substituted cycloalkenyl each having 5 to 8 ring members, phenyl or A-substituted phenyl, naphthyl or A-substituted naphthyl, a heterocyclic group selected from the group consisting of heteroaromatic and heteroalicyclic groups having from 1 to 2 rings, from 3 to 8 ring members in each ring, and from 1 to 4 hetero atoms selected from oxygen, nitrogen, and sulfur, alkoxy or alkythio each having 1 to 6 carbon atoms, carboxy, alkoxycarbonyl having 1 to 7 carbon atoms, phenoxycarbonyl or A-substituted phenoxy, naphthoxy or A-substituted naphthoxy, alkoxycarbonylamino having 2 to 6 carbon atoms, guanidino, ureido (--NHCONH 2 ), N-alkylureylene (--NHCONHalkyl) having 2 to 7 carbon atoms, N 3  -haloalkylureylene having 3 to 7 carbon atoms, N 3  -haloalkyl-N 3  -nitrosoureylene having 3 to 7 carbon atoms, and dialkylaminocarbonyl having 3 to 13 carbon atoms, wherein said A substituent is selected from the group consisting of one or two lower alkyl, lower alkanoyl, lower alkoxy, halo, amino, hydroxy, or nitro groups. The entire disclosure of U.S. Ser. No. 581,291 is incorporated herein by reference. 
     In the operation of the present process a number of novel compounds of Formula IX have been produced. These compounds have antitumor activity and inhibit the growth of experimental animal tumors. They are considered part of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The reagent employed in the present process in reaction with thiols of the Formula R 9  SH is referred to as Compound No. 30. The preparation thereof is described in U.S. Ser. No. 581,291 in Procedure No. 30 where it is also referred to as Compound No. 30. This is a particularly preferred reactant because of the stability of the by-product 3-nitro-2-pyridyldthione which is produced in the process and which is believed to provide a driving force for completion of the reaction. A similar disulfide thiol exchange process has been described by Kono et al. in European Patent Application Publication No. 0116208 published Aug. 22, 1984. In that process the 2-pyridylsulfide corresponding in structure to Compound No. 30 is employed. 3-Nitro-1-pyridylthione is a more facile leaving group, and as a result the present process enjoys certain advantages over that process. 
     The process as described in the above reaction scheme takes place at a temperature in the range of 0 to 60 deg. C., the particular temperature being chosen on the basis of the reactivity of the thiol and the stability of the product produced. The reaction is carried out in a reaction inert liquid medium preferably one in which the reactants are soluble. At least one chemical equivalent of the thiol R 9  SH relative to Compound 30 is employed. It is preferable to carry out the reaction in the presence of a base such as a tertiary amine. With water-soluble thiol reactants, water may be used as the reaction inert liquid medium and sodium bicarbonate is preferred as the base. Approximately one chemical equivalent of base per quantity of Compound 30 is employed. Suitable reaction inert liquid media include lower alkanols, such as methanol, ethanol, and isopropanol, lower alkanoic lower alkyl esters such as ethyl acetate, methyl propionate, and butyl acetate may be employed. Other appropriate reaction media include lower aliphatic ketones such as acetone and methylethyl ketone, cyclic aliphatic ethers such as tetrahydrofuran and lower polyhalogenated aliphatic hydrocarbons such as methylene chloride, ethylene dichloride, and chloroform. 
     DESCRIPTION OF SPECIFIC EMBODIMENTS 
     In the following procedures and examples, all temperatures are given in degrees centigrade, and melting points are uncorrected. Proton nuclear magnetic resonance ( 1  H NMR) spectra were recorded on Joel FX-90Q or Bunker VM 360 spectrometer in either pyridine-d 5  or D 2  O as indicated. When pyridine-d 5  was used as the solvent, the pyridine resonance at 8.57 PPM was used as an internal reference, whereas with D 2  O as solvent trimethylsilylpropane sulfonic acid (TSP) was used as the internal reference. Chemical shifts are reported in parts per million (PPM), and integrals proportional to the areas under each shift are reported. Where splitting patterns are given, the following abbreviations are used: s, singlet; d, doublet; t, triplet; q, quartet; m, multiplet; bs, broad singlet; dd, double of doublets; dt, doublet of triplets. Where they are not given, the data presented are sufficient to provide such analysis if desired. Infrared spectra (IR) were determined either on a Beckman Model 4240 spectrometer or a Nicolet 5DX FT-IR spectrometer and are reported in reciprocal centimeters. Ultraviolet (UV) spectra were determined either on a Cary Model  290 spectrometer or a Hewlitt Packard 8450A spectrometer equipped with a multidiode array detector. Thin layer chromatography (TLC) was carried out on 0.25 mm Analtech silica gel GF plates or Whatmann MK6F silica gel plates. Flash chromatography was run with either Woelm neutral alumina (DCC grade) or Woelm silica gel (32-63 μm) and the indicated solvents. Reverse phase high pressure liquid chromatography (HLPC) was performed on μ  Bondpack-C 18  column using Waters 6000 pump which is equipped with a Waters 440 UV detector. Reverse phase column chromatography was performed using C-18 silica gel in solvents indicated. All evaporations of solvents were performed under reduced pressure and below 40 eg. C. 
     The process was applied in one of two procedures using various thiols as reactant with 7-[2-(3-nitro-2-pyridyldithio)ethylamino]-9a-methoxymitosane. The latter has been previously described in application Ser. No. 581,291 filed Feb. 24, 1984 and its preparation more particularly below. 
     7-[2-(3-Nitro-2-pyridyldithio)ethylamino]-9a-methoxymitosane 
     To a solution of 7-dimethylaminomethyleneamino-9a-methoxymitosane (1.0 g, 2.61 mM) in deoxygenated methanol (15 ml) was added triethylamine (1.1 ml, 7.83 mM) under stirring and ice bath temperature (0 deg. ca. 4 deg. C.). The reaction mixture was sonicated and allowed to stir at ca. 22 deg. C. for 24 hours. Thin layer chromatography (silica gel, 10% CH 3  OH in CH 2  Cl 2 ) revealed that &gt;90% of the starting compound (green) had been converted to the desired blue compound. The reaction mixture was concentrated under reduced pressure and the resulting residue was chromatographed in 1&#34;×16&#34; column packet with silica gel in 5% MeOH in CH 2  Cl 2 . Gradient elution with MeOH, 1-5% v/v in CH 2  Cl 2  afforded the title compound as a pure bluish amorphous solid (430 mg). The spectral properties of this material are in agreement with those reported in U.S. Ser. No. 582,291. 
     Method A--Preferred For Lipophilic Products 
     To a deoxygenated solution of 7-[2-(3-nitro-2-pyridyldithio)ethylamino]-9a-methoxymitosane (ca. 1.1 equiv.) in acetone (3-5 ml) is added with stirring, under an argon or nitrogen atmosphere, triethylamine (ca. 1.1 equiv.) followed by dropwise or portionwise addition of the thiol reactant (1 equiv.) in acetone (1-2 ml). The progress of the reaction is monitored by silica gel thin layer chromatography (10% MeOH in CH 2  Cl 2 ), unless the starting nitropyridyldithio mitosane reactant and the product have similar Rf values. In such instances HPLC monitoring is employed (μ Bondpack-C 18 ). The completion of the reaction is apparent when disappearance of the reactant and appearance of the product occurs. At this point the reaction mixture is concentrated under reduced pressure (ca. 30 deg. C.) and the residue chromatographed on a neutral Woelm alumina column (1/4×10&#34;) packed employing 2-5% MeOH in CH 2  Cl 2  for slurrying. This procedure separates the desired mitosane product from the pyridyl thione byproduct which remains on the column. The product thus eluted using 2% MeOH in CH 2  Cl 2  is further purified by flash silica gel chromatography using 5-7%. MeOH in CH 2  Cl 2  as the eluting solvent. The major band corresponding to product is isolated and the amorphous product characterized. 
     Examples 1-25 employ method A applied to various neutral lipophilic thiols or those containing basic groups. 
     Method B--Preferred for Hydrophilic Products 
     To solution of 7-[2-(3-nitro-2-pyridyldithio)ethylamino]-9a-methoxymitosane (ca. 0.1 mM) in methanol (10 ml) containing 2-5% v/v of acetone (or 2-5% v/v methylene chloride) is added sat. aq. NaHCO 3  solution (6 drops), and a methanolic solution of 1 chemical equivalent of the thiol, volume ca. 1 ml water may be used as solvent for the thiol if the water solubility thereof is sufficient. The progress of the reaction is monitored by thin layer chromatography (silica gel, 10% MeOH in CH 2  Cl 2 ). At the completion of reaction, the reaction mixture is diluted with water (15 ml) and concentrated to ca. 10 ml on a rotavapor at 30 deg. C. The resulting solution is chromatographed on a reverse phase C-18 column with stepwise gradient elution (100% H 2  O to 80% MeOH in H 2  O). The product is eluted after elution of the by-product thione at the increased methanol concentrations. The product appears as a major blue fraction, which is collected, and concentrated to yield an amorphous solid. If further purification is needed the above chromatograph step is repeated. 
     Examples 26-30 employ Method B applied to various thiols containing salt-forming groups. 
     EXAMPLE 1 
     7-[2-(4-Chlorophenyldithio)ethylamino]-9a-methoxymitosane (39).--Method A employing 4-chlorothiophenol 
       1  H NMR data (pyridine d 5 ): 
     
         ______________________________________FREQUENCY    PPM        INTEGRAL______________________________________3143.874     8.7297     .7182739.107     7.6058     .1112729.688     7.5796     1.0522721.412     7.5567     .5932718.682     7.5491     .0972669.282     7.4119     .5852667.385     7.4066     .1082662.528     7.3932     .1182660.613     7.3878     .3672650.480     7.3597     .0642608.945     7.2444     .1842602.620     7.2268     .2822596.156     7.2089     .9841954.657     5.4276     .1891950.505     5.4161     .1441944.312     5.3989     .1701940.091     5.3871     .1641847.791     5.1308     .2031837.219     5.1015     .2711826.720     5.0723     .1801774.500     4.9273     2.8841637.494     4.5469     .3371624.753     4.5115     .3341452.696     4.0338     .1681448.520     4.0222     .1721441.467     4.0026     .1711437.340     3.9911     .1571404.385     3.8996     .2211397.740     3.8812     .4551391.049     3.8626     .4541384.386     3.8441     .1961302.465     3.6166     .3511290.130     3.5824     .2681178.026     3.2711     .0771164.985     3.2349     1.8501134.073     3.1490     .6261095.041     3.0406     .3901088.318     3.0220     .6081081.611     3.0034     .307992.057      2.7547     .684772.470      2.1450     .197766.114      2.1273     .340734.164      2.0386     1.886-.000        -.0000     2.063______________________________________ 
    
     IR (KBr, ν max , cm -1 ): 3440, 3280, 2950, 1720, 1635, 1560, 1510, 1474, 1450, 1325, 1060. 
     UV (MeOH, λ max , nm): 368, 238(sh), 220. 
     EXAMPLE 2 
     7-[2-(4-Bromophenyldithio)ethylamino]-9a-methoxymitosane (47).--Method A employing 4-bromothiophenol 
       1  H NMR data (pyridine d 5 ): 
     
         ______________________________________FREQUENCY    PPM        INTENSITY______________________________________3086.651     8.5709     89.6712692.567     7.4766     1.3602670.818     7.4162     68.6212659.543     7.3849     6.1612657.684     7.3797     16.5912648.749     7.3549     17.5572641.944     7.3360     4.2392639.909     7.3304     8.3642638.621     7.3268     9.9692626.614     7.2935     2.4012624.367     7.2872     7.6732617.778     7.2689     2.2702615.699     7.2632     4.3122587.041     7.1836     1.3222582.594     7.1712     1.0492578.892     7.1610     1.0832551.216     7.0841     3.9862538.742     7.0495     81.0021898.031     5.2704     2.6881893.978     5.2591     2.4991887.686     5.2417     3.4131883.492     5.2300     2.7971778.104     4.9374     1.2831727.439     4.7967     13.8891581.651     4.3919     4.8121575.060     4.3736     1.5341568.837     4.3563     4.9921395.824     3.8759     2.8291391.542     3.8640     2.9311384.700     3.8450     3.0591380.440     3.8332     2.5211345.894     3.7372     2.2651339.257     2.7188     6.1271332.587     3.7003     6.5131325.939     3.6818     2.7541247.979     3.4653     1.6991235.355     3.4303     1.6471109.433     3.0806     12.7991107.467     3.0752     43.9841097.943     3.0487     1.3011090.735     3.0287     1.2841084.521     3.0115     2.4651078.013     2.9934     2.8251035.937     2.8765     4.6351029.085     2.8575     8.0151022.373     2.8389     4.583934.207      2.5941     2.907920.895      2.5571     2.572715.422      1.9866     1.426676.497      1,8785     29.005______________________________________ 
    
     EXAMPLE 3 
     7-[2-(4-Fluorophenyldithio)ethylamino]-9a-methoxymitosane (46).--Method A employing 4-fluorothiophenol 
       1  H NMR data (pyridine d 5 ): 
     
         ______________________________________FREQUENCY    PPM        INTENSITY______________________________________3094.793     8.5935     2.9493086.092     8.5693     71.4002692.617     7.4767     3.2352687.390     7.4622     3.9802684.098     7.4531     4.2652678.931     7.4387     5.8982670.028     7.4140     53.7862547.257     7.0731     3.8422538.009     7.0474     68.6312523.997     7.0085     7.5432515.342     6.9845     3.8611897.552     5.2690     1.4991893.349     5.2574     1.6231887.153     5.2401     1.9381883.067     5.2288     1.8011779.560     4.9414     1.3181722.527     4.7830     12.5661578.645     4.3835     2.9311565.979     4.3483     3.2341394.123     3.8711     1.7391389.902     3.8594     2.0781382.885     3.8399     1.8551378.856     3.8287     1.7061351.510     3.7528     1.4691344.836     3.7343     4.0571338.216     3.7159     4.4631331.635     3.6976     2.0771244.124     3.4546     1.2931231.741     3.4202     1.2221106.270     3.0718     21.9731083.640     3.0090     1.3981077.831     2.9929     1.6531039.104     2.8853     3.1991032.385     2.8667     5.9331025.696     2.8481     3.204932.666      2.5898     1.743711.666      1.9761     1.244693.178      1.9248     1.762679.305      1.8863     16.668______________________________________ 
    
     IR (KBr, ν max , cm -1 ): 3430, 3290, 2920, 1720, 1640, 1560, 1510, 1450, 1330, 1220, 1060. 
     UV (MeOH, λ max , nm): 370, 222. 
     EXAMPLE 4 
     7-[2-(2-Chlorophenyldithio)ethylamino]-9a-methoxymitosane (55).--Method A employing 2-chlorothiophenol 
       1  H NMR data (pyridine d 5 ): 
     
         ______________________________________FREQUENCY    PPM        INTENSITY______________________________________3086.658     8.5709     354.9202789.230     7.7450     3.7882781.178     7.7226     3.9032670.412     7.4151     203.1982637.641     7.3241     1.2512619.047     7.2724     2.5382608.912     7.2443     4.0082601.011     7.2224     4.9912589.766     7.1911     4.8022582.103     7.1699     2.6842538.357     7.0484     328.9542523.173     7.0062     5.0842515.145     6.9839     2.7551896.130     5.2651     1.9171891.886     5.2533     2.0571885.611     5.2359     2.2621881.627     5.2248     2.6011778.080     4.9373     1.1201730.238     4.8044     7.5221574.972     4.3733     3.7651562.242     4.3380     4.0631392.854     3.8676     2.1961388.576     3.8557     2.0541381.591     3.8363     2.0361377.677     3.8255     1.7221349.813     3.7481     1.6651342.946     3.7290     4.1421336.349     3.7107     4.2171329.647     3.6921     1.9631245.714     3.4590     1.6251234.390     3.4276     1.4481104.953     3.0682     28.5341074.486     2.9836     2.3191031.569     2.8644     3.9101024.929     2.8460     7.1451018.285     2.8275     3.493932.398      2.5890     2.552814.080      2.2605     1.350723.808      2.0098     1.102677.286      1.8807     23.661______________________________________ 
    
     EXAMPLE 5 
     7-[2-(2-Bromophenyldithio)ethylamino]-9a-methoxymitosane (65).--Method A employing 2-bromothiophenyl 
       1  H NMR data (pyridine d 5 ): 
     
         ______________________________________FREQUENCY    PPM        INTENSITY______________________________________3088.884     8.5771     89.7912790.861     7.7495     1.8582783.064     7.7279     1.8132673.036     7.4223     53.9652664.964     7.3999     2.4212618.223     7.2701     1.1132610.639     7.2491     1.7622602.928     7.2277     1.1022541.000     7.0557     85.5662503.916     6.9527     1.0662496.358     6.9318     1.6341897.870     5.2699     1.0131893.745     5.2585     1.0021887.532     5.2412     1.1211883.415     5.2298     1.0571786.096     4.9595     .9671722.377     4.7826     6.9181576.483     4.3775     1.6241563.921     4.3426     1.6081394.999     3.8736     1.1791390.756     3.8618     1.2501383.913     3.8428     1.1221379.766     3.8313     .9931344.182     3.7325     2.0051337.507     3.7139     2.0711330.434     3.6943     .8861246.383     3.4609     1.4481233.693     3.4257     .8681107.612     3.0756     13.5421079.502     2.9975     1.0121033.690     2.8703     1.9641026.784     2.8511     3.4631020.295     2.8331     1.614934.405      2.5946     1.081712.878      1.9795     .946680.366      1.8892     8.887______________________________________ 
    
     EXAMPLE 6 
     7-[2-(2,6-Dichlorophenyldithio)ethylamino]-9a-methoxymitosane (52).--Method A employing 2,6-dichlorothiophenol 
       1  H NMR data (pyridine d 5 ): 
     
         ______________________________________FREQUENCY    PPM        INTENSITY______________________________________3096.025     8.5969     8.9893086.614     8.5707     262.2132757.647     7.6573     1.5022749.367     7.6343     2.2182681.319     7.4453     6.5462670.136     7.4143     186.2732628.286     7.2981     6.8632620.169     7.2755     9.7172609.009     7.2446     5.9662600.963     7.2222     7.4382588.248     7.1869     2.1172575.576     7.1517     2.0862547.255     7.0731     10.3602538.154     7.0478     246.9872480.023     6.8864     2.3212456.668     6.8215     1.8521887.908     5.2422     2.3961883.629     5.2304     2.8721877.625     5.2137     2.7601873.527     5.2023     2.3331769.319     4.9130     1.8691731.124     4.8069     27.1381574.128     4.3710     3.6461568.549     4.3555     2.2071561.432     4.3357     3.7441393.054     3.8682     1.6001378.772     3.8285     5.5971371.943     3.8095     5.8061247.970     3.4653     2.4671234.722     3.4285     2.4531106.516     3.0725     5.4041102.314     3.0608     31.2171084.696     3.0119     2.8851078.844     2.9957     5.6111073.435     2.9807     7.6111059.705     2.9425     1.6951029.741     2.8593     1.9061022.765     2.8400     2.499931.917      2.5877     3.399920.768      2.5567     3.018715.360      1.9864     7.831694.846      1.9294     20.393680.187      1.8887     2.738______________________________________ 
    
     EXAMPLE 7 
     7-[2-(2,4-Dichlorophenyldithio)ethylamino]-9a-methoxymitosane (50).--Method A employing 2,4-dichlorothiophenol 
       1  H NMR data (pyridine d 5 ): 
     
         ______________________________________FREQUENCY    PPM        INTENSITY______________________________________3104.914     8.6216     1.9223095.765     8.5962     4.0523086.609     8.5707     182.0922757.604     7.6572     5.7582748.941     7.6331     6.1432680.773     7.4438     2.4312670.316     7.4148     91.1682649.396     7.3567     2.9422647.244     7.3507     3.0442642.923     7.3387     4.7352640.803     7.3328     5.3302618.698     7.2715     1.6142614.924     7.2610     3.8142612.799     7.2551     3.4102606.232     7.2369     2.7802604.107     7.2310     2.6352581.846     7.1691     2.3912579.685     7.1631     2.3062573.061     7.1447     2.7462571.061     7.1392     2.5372565.809     7.1246     2.7592557.328     7.1011     2.3892549.032     7.0780     3.2302538.315     7.0483     160.7961897.970     5.2702     2.2121893.650     5.2582     2.7221887.692     5.2416     2.8931883.310     5.2295     3.0841732.330     4.8102     7.5761578.543     4.3832     3.9681565.749     4.3477     4.4561395.962     3.8762     2.5441391.700     3.8644     2.7051384.733     3.8451     2.7831380.505     3.8333     2.4951353.560     3.7585     1.7981346.688     3.7394     4.1961339.996     3.7208     4.3431333.396     3.7025     2.1761247.381     3.4637     2.1131234.770     3.4286     1.9961106.762     3.0732     30.6941103.861     3.0651     9.7331097.728     3.0481     1.7411072.702     2.9786     2.5311037.593     2.8811     3.3721030.795     2.8623     6.4511023.941     2.8432     4.061932.000      2.5879     2.626715.409      1.9865     5.066680.055      1.8883     20.943______________________________________ 
    
     EXAMPLE 8 
     7-[2-(3-Chlorophenyldithio)ethylamino]-9a-methoxymitosane (58).--Method A employing 3-chlorothiophenol 
       1  H NMR data (pyridine d 5 ): 
     
         ______________________________________FREQUENCY    PPM        INTENSITY______________________________________3085.348     8.5672     71.3642713.519     7.5348     4.4912669.389     7.4122     42.7332641.517     7.3348     2.4202635.412     7.3179     2.6382617.780     7.2689     1.1982571.300     7.1399     2.4742563.321     7.1177     5.3022557.187     7.1007     8.0242537.316     7.0455     69.1301894.009     5.2592     1.7111889.794     5.2475     1.8051883.499     5.2300     1.9071879.433     5.2187     1.7771778.965     4.9397     1.3521724.502     4.7885     3.2651575.192     4.3739     2.8621562.650     4.3391     2.7791392.023     3.8653     1.8111387.906     3.8539     1.9481381.000     3.8347     1.9551376.859     3.8232     1.6661344.147     3.7324     1.7811337.633     3.7143     3.4851331.146     3.6963     3.4851324.709     3.6784     1.7151243.697     3.4534     1.3651231.901     3.4207     1.3571104.883     3.0680     17.2101073.619     2.9812     1.8801033.597     2.8700     3.3161026.901     2.8514     5.1491020.257     2.8330     2.821932.403      2.5890     2.072710.311      1.9724     1.386692.134      1.9219     1.843674.921      1.8741     14.080______________________________________ 
    
     EXAMPLE 9 
     7-[2-(2,5-Dichlorophenyldithio)ethylamino]-9a-methoxymitosane (57).--Method A employing 2,5-dichlorothiophenol 
       1  H NMR data (pyridine d 5 ): 
     
         ______________________________________FREQUENCY    PPM        INTENSITY______________________________________3085.997     8.5690     93.1512789.295     7.7452     2.5222788.014     7.7416     2.4612781.668     7.7240     2.6722670.153     7.4143     52.3892662.006     7.3917     1.0222637.937     7.3249     .8172619.105     7.2726     1.2272608.923     7.2443     2.8962607.821     7.2413     2.9142600.569     7.2211     3.1372597.281     7.2120     1.9962589.809     7.1912     3.3152581.491     7.1681     2.2662577.499     7.1571     1.3122573.116     7.1449     1.5652538.173     7.0479     85.5262530.928     7.0278     2.4292523.065     7.0059     2.3362521.838     7.0025     2.3122515.673     6.9854     1.3852514.297     6.9816     1.2491894.281     5.2599     1.7311889.986     5.2480     1.9351883.930     5.2312     1.9551879.631     5.2193     1.8231778.344     4.9380     1.0341721.287     4.7796     2.7831573.832     4.3701     3.2071561.153     4.3349     3.0941391.698     3.8644     1.7931387.597     3.8530     1.9781380.523     3.8334     1.8091376.417     3.8220     1.5271349.161     3.7463     1.4451342.688     3.7283     3.0301335.992     3.7097     3.1091329.527     3.6918     1.4801245.053     3.4572     1.1191233.053     3.4239     1.0551109.056     3.0796     4.2271104.734     3.0676     21.5811083.720     3.0092     1.3291077.008     2.9906     1.5261031.596     2.0645     3.0391024.781     2.0456     4.8201017.982     2.8267     2.464933.976      2.5934     1.604837.857      2.3265     1.306835.753      2.3207     1.763833.609      2.3147     2.246831.269      2.3082     1.735709.321      1.9696     1.093692.847      1.9239     2.684677.031      1.8799     14.762______________________________________ 
    
     IR(KBr, ν max  cm -1 ): 3450, 3290, 2930, 1720, 1640, 1560, 1515, 1475, 1455, 1330, ±065. 
     UV(MeOH, ν max  nm): 367, 218. 
     EXAMPLE 10 
     7-[2-(3,4-Dichlorophenyldithio)ethylamino]-9a-methoxymitosane (61).--Method A applied to 3,4-dichlorothiophenol 
       1  H NMR data (pyridine) d 5 ): 
     
         ______________________________________FREQUENCY    PPM        INTENSITY______________________________________3084.858     8.5659     22.6512737.563     7.6015     6.9552669.762     7.4133     14.0632640.258     7.3313     2.5082631.654     7.3074     11.8442621.027     7.2779     1.3712552.501     7.0877     3.1092546.297     7.0704     5.0722537.654     7.0464     22.1161894.292     5.2600     2.5361890.094     5.2483     2.5061883.970     5.2313     2.8551879.783     5.2197     2.4301772.587     4.9220     1.4141576.225     4.3768     4.0991563.539     4.3416     4.2121393.191     3.8685     2.7741389.009     3.8569     2.8181381.991     3.8374     2.7141377.894     3.8261     2.2741349.938     3.7484     2.6761343.449     3.7304     5.6501336.929     3.7123     5.6511330.508     3.6945     2.5131246.457     3.4611     2.1361234.069     3.4267     1.9331106.375     3.0721     27.8961073.644     2.9812     3.0911044.916     2.9015     4.7991038.298     2.8831     7.7791031.673     2.8647     3.943933.135      2.5911     3.175919.103      2.5521     1.877712.794      1.9792     1.524708.146      1.9663     1.502676.000      1.8771     23.605______________________________________ 
    
     EXAMPLE 11 
     7-[2-(3-Trifluoromethylphenyldithio)ethylamino]-9a-methoxymitosane (51).--Method A applied to 3-trifluoromethylthiophenol 
       1  H NMR data (pyridine d 5 ): 
     
         ______________________________________FREQUENCY    PPM        INTENSITY______________________________________3096.041     8.5969     3.9793086.601     8.5707     191.3942816.428     7.8205     4.0462766.458     7.6817     2.6142759.037     7.6111     2.9442680.739     7.4437     2.3542670.277     7.4147     94.7282653.288     7.3675     4.5652646.995     7.3500     3.3642639.249     7.3285     3.5132549.619     7.0796     4.0142538.277     7.0481     168.3331890.555     5.2496     2.0541884.287     5.2322     2.2691880.154     5.2207     2.2441730.088     4.8040     36.4621573.873     4.3702     3.6491561.173     4.3350     3.9931391.847     3.8648     2.1331387.644     3.8531     2.3071380.627     3.8336     2.2051342.397     3.7275     3.8871335.818     3.7092     4.2711109.074     3.0796     2.6221104.563     3.0671     31.7551046.186     2.9050     3.5311039.326     2.8859     6.4321032.615     2.8673     3.667932.644      2.5897     2.040671.477      1.8645     21.716______________________________________ 
    
     EXAMPLE 12 
     7-[2-(3-Methoxyphenyldithio)ethylamino]-9a-methoxymitosane (54).--Method A applied to 3-methoxythiophenol 
       1  H NMR data (pyridine d 5 ): 
     
         ______________________________________FREQUENCY       PPM     INTENSITY______________________________________3086.415        8.5702  562.7242670.763        7.4160  276.0992590.589        7.1934  24.2122588.595        7.1879  34.7602586.537        7.1822  24.6742584.829        7.1774  15.8562576.794        7.1551  33.2092563.954        7.1333  30.0012561.309        7.1121  34.1292560.105        7.1088  23.5502553.236        7.0897  20.3672533.633        7.0491  496.4302526.218        7.0147  8.1942425.701        6.7356  15.3792422.569        6.7269  14.3072417.424        6.7126  12.7492415.676        6.7077  13.0451892.375        5.2560  14.1431888.677        5.2444  14.2281882.529        5.2273  17.2851873.267        5.2155  15.5371772.130        4.9208  5.7091719.455        4.7745  11.0351576.419        4.3773  26.7981563.627        4.3418  28.1241391.474        3.8638  13.7691337.333        3.8523  14.6721380.333        3.8328  15.2881376.094        3.3211  12.4701352.786        3.7563  9.5571345.640        3.7365  22.5011338.800        3.7175  23.3081332.158        3.6991  9.7261281.868        3.5594  236.2111246.777        3.4620  9.7171234.477        3.4278  8.7591106.624        3.0728  235.0811074.832        2.9845  13.4221070.883        2.9736  13.3781040.474        2.8891  26.3381033.789        2.8706  50.4601026.992        2.8517  22.622932.644         2.5897  14.174920.731         2.5566  8.501693.444         1.9255  8.385677.749         1.8819  156.816664.377         1.8448  18.786461.026         1.2802  32.173______________________________________ 
    
     IR(KBr, ν max  cm -1 ): 3450, 3300, 2930, 1720, 1638, 1560, 1515, 1478, 1450, 1330, 1065. 
     UV(MeOH, ν max , nm): 368, 216. 
     EXAMPLE 13 
     7-[2-(2-Methoxyphenyldithio)ethylamino]-9a-methoxymitosane (56).--Method A applied to 2-methoxythiophenol 
       1  H NMR data (pyridine d 5 ): 
     
         ______________________________________FREQUENCY       PPM     INTENSITY______________________________________3086.515        8.5705  103.5472778.944        7.7164  4.1682771.012        7.6944  4.0812670.705        7.4159  51.8502568.761        7.1328  2.9672561.119        7.1116  4.4692553.130        7.0894  4.2822538.673        7.0493  98.7372501.730        6.9467  3.0672494.323        6.9261  4.5032486.601        6.9047  1.9932434.187        6.7591  4.8652426.072        6.7366  4.2911892.531        5.2551  2.9521888.248        5.2432  2.9791882.191        5.2264  3.3501877.909        5.2145  3.2331769.650        4.9139  2.0761577.497        4.3803  4.4011564.771        4.3450  4.7741390.507        3.8611  2.8721386.070        3.8488  3.2491379.349        3.8301  3.0961375.131        3.8184  2.8051370.459        3.8054  1.7691363.138        3.7851  3.1471356.287        3.7661  5.3821349.565        3.7474  5.1721342.957        3.7291  2.2231289.212        3.5798  33.1371247.557        3.4642  3.0631235.150        3.4297  2.8661104.941        3.0681  37.4991074.634        2.9840  4.0351070.446        2.9724  4.1521034.998        2.8739  4.4811028.277        2.8553  7.8731021.667        2.8369  4.503933.058         2.5909  3.839715.577         1.9870  6.097682.593         1.8954  24.161______________________________________ 
    
     IR(KBr, ν max , cm -1 ): 3450, 3300, 2930, 1720, 1635, 1560, 1515, 1450, 1330, 1065. 
     UV(MeOH, ν max , nm): 209, 214, 367. 
     EXAMPLE 14 
     7-[2-(2-Aminophenyldithio)ethylamino]-9a-methoxymitosane (62).--Method A applied to 2-aminothiophenol 
       1  H NMR data (pyridine d 5 ): 
     
         ______________________________________FREQUENCY       PPM     INTENSITY______________________________________3086.382        8.5701  86.7322671.205        7.4173  62.9832578.881        7.1609  3.3002572.379        7.1428  5.6632566.135        7.1255  3.4592538.819        7.0497  80.6091981.127        5.5011  3.5551891.642        5.2526  3.6011887.582        5.2413  3.8041881.369        5.2241  4.2951877.286        5.2128  4.0021787.037        4.9622  2.2151776.461        4.9328  3.2161765.421        4.9021  2.1131726.603        4.7943  5.7061580.362        4.3883  6.6411567.711        4.3531  7.1231396.170        3.8768  4.7611391.953        3.8651  5.3481385.027        3.8459  5.7511380.690        3.8338  5.4371377.505        3.8250  5.0331370.775        3.8063  8.7891364.034        3.7876  8.3291357.381        3.7691  3.4881244.058        3.4544  55.7421230.981        3.4181  3.3831104.203        3.0661  59.4681095.831        3.0428  2.0871074.561        2.9838  3.6471030.274        2.8608  7.3631023.508        2.8420  11.9921016.755        2.8233  6.322931.694         2.5871  4.183715.588         1.9870  34.595______________________________________ 
    
     EXAMPLE 15 
     7-[2-(4-Aminophenyldithio)ethylamino]-9a-methoxymitosane (43).--Method A applied to 4-aminothiophenol 
       1  H NMR data (pyridine d 5 ): 
     
         ______________________________________FREQUENCY       PPM      INTENSITY______________________________________3097.058        8.5997   2.0743086.103        8.5693   63.4462682.029        7.4473   1.9282670.785        7.4161   42.2632654.773        7.3716   4.9572646.488        7.3486   4.9792549.849        7.0803   2.1252538.595        7.0490   61.7932510.432        6.9708   1.3302423.093        6.7283   4.2932414.889        6.7055   4.1332093.654        5.8135   4.1591902.189        5.2819   1.4101897.989        5.2702   1.5331891.815        5.2531   1.8011887.650        5.2415   1.7911788.714        4.9668   1.2281722.452        4.7828   1.9201711.799        4.7532   51.9571581.821        4.3923   2.5861569.146        4.3571   2.8531390.464        3.8609   1.6031386.294        3.8494   1.8121379.299        3.8299   1.8381375.107        3.8183   1.7641371.339        3.8078   1.1791364.417        3.7886   2.6201358.048        3.7709   2.9191351.641        3.7531   1.4321241.435        3.4471   1.1811228.989        3.4126   1.0761105.040        3.0684   1.7181100.481        3.0557   19.0331091.834        3.0317   1.0201086.003        3.0155   1.0501078.584        2.9949   1.2681056.956        2.9349   1.2821050.624        2.9173   2.0371046.337        2.9054   1.7541039.661        2.8869   2.3591032.701        2.8675   1.549930.333         2.5833   1.355723.295         2.0084   1.102698.719         1.9402   14.859689.544         1.9147   2.050558.101         1.5497   1.018461.045         1.2802   1.183-56.758         -.1576   35.127______________________________________ 
    
     IR(KBr, ν max  cm -1 ): 3440, 3360, 3290, 2940, 1720, 1635, 1600, 1510, 1300, 1330. 
     UV(MeOH, λ max  nm): 218, 369. 
     EXAMPLE 16 
     7-[2-(3-Aminophenyldithio)ethylamino]-9a-methoxymitosane (53).--Method A applied to 3-aminothiophenol 
       1  H NMR data (pyridine d 5 ): 
     
         ______________________________________FREQUENCY       PPM     INTENSITY______________________________________3086.871        8.5715  374.9902691.699        7.4742  2.5042682.064        7.4474  6.1532670.593        7.4156  273.1312588.581        7.1878  2.2712571.392        7.1401  4.0982569.555        7.1350  6.1592559.811        7.1080  2.8052549.477        7.0793  7.5062538.555        7.0489  343.2062527.557        7.0184  10.5122463.709        6.8411  3.1092456.158        6.8201  4.6942408.230        6.6870  2.7052400.366        6.6652  2.4542398.758        6.6607  2.4712044.665        5.6775  3.7371895.598        5.2636  1.7601891.482        5.2522  1.8741885.412        5.2353  2.2691881.100        5.2233  2.0741730.133        4.8041  64.7901579.573        4.3861  3.8511566.945        4.3510  4.1311392.672        3.8671  2.4231388.477        3.8555  2.4391381.578        3.8363  2.4111377.292        3.8244  2.1381347.946        3.7429  1.6461340.937        3.7234  3.9081334.439        3.7054  4.1301327.335        3.6857  1.7811103.126        3.0631  32.5731072.236        2.9773  1.6921016.905        2.8237  4.0411010.123        2.8049  7.3291003.221        2.7857  3.777929.798         2.5818  1.966714.778         1.9848  1.619685.856         1.9044  16.898______________________________________ 
    
     EXAMPLE 17 
     7-[2-(4-Hydroxyphenyldithio)ethylamino]-9a-methoxymitosane (42).--Method A applied to 4-hydroxythiophenol 
       1  H NMR data (pyridine d 5 ): 
     
         ______________________________________FREQUENCY  PPM       INTEGRAL   INTENSITY______________________________________3136.440   8.7090    6.424      68.7012747.803   7.6299    1.242      15.1542739.247   7.6061    1.336      17.7302731.869   7.5856    .348       3.8232721.298   7.5563    5.725      46.4762598.368   7.2149    .269       2.5152589.146   7.1893    7.546      69.9142573.746   7.1466    .152       5.7632570.616   7.1379    1.138      17.9602562.036   7.1140    1.301      16.4931949.364   5.4128    .230       4.0491945.208   5.4013    .291       4.5991938.860   5.3837    .304       5.4031934.844   5.3725    .367       5.4441821.705   5.0584    1.429      3.9161810.519   5.0273    .516       3.9811776.864   4.9338    10.877     17.8111637.246   4.5462    .514       7.8551624.515   4.5108    .679       8.5971442.851   4.0064    .315       4.3391438.819   3.9952    .305       5.0981431.777   3.9756    .289       5.1091427.713   3.9644    .266       5.2191423.796   3.9535    .310       4.5581417.071   3.9348    .781       10.3711410.591   3.9168    .886       10.8941404.165   3.8990    .429       4.6411294.248   3.5938    2.282      32.7751285.005   3.5681    .744       5.3151154.198   3.2049    3.627      58.9651129.182   3.1354    .453       5.1151125.913   3.1263    .766       5.9421103.171   3.0632    .560       6.4111096.485   3.0446    .924       11.6531089.858   3.0262    .625       6.432982.320    2.7276    1.199      5.800765.778    2.1263    .369       3.738748.336    2.0779    3.529      45.305______________________________________ 
    
     EXAMPLE 18 
     7-[2-(1-Phenylethylidithio)ethylamino]-9a-methoxymitosane (48).--Method A applied to 1-phenylethane thiol 
       1  H NMR data (partial, pyridine d 5 ): 
     
         ______________________________________FREQUENCY  PPM       INTEGRAL   INTENSITY______________________________________1952.473   5.4215    .091       5.1041948.316   5.4100    .090       5.5131942.104   5.3927    .112       6.4181938.031   5.3814    .090       6.0331848.588   5.1331    .076       2.4411837.836   5.1032    .148       4.2391827.564   5.0747    .057       1.8811775.213   4.9293    .639       20.6161639.982   4.5538    .198       12.9171627.323   4.5187    .205       14.1961521.186   4.2239    .011       1.9131519.505   4.2193    .025       1.9501514.020   4.2040    .075       6.7851512.644   4.2002    .072       6.6061507.161   4.1850    .089       7.2001505.450   4.1803    .056       6.9451500.096   4.1654    .019       1.8561498.683   4.1615    .015       1.7411450.041   4.0264    .102       7.2681445.788   4.0146    .109       7.9751438.875   3.9954    .116       7.7961434.671   3.9837    .078       6.4151377.618   3.8253    .123       5.2781370.918   3.8067    .352       14.6141364.196   3.7880    .325       14.7741357.461   3.7693    .096       5.1201302.525   3.6168    .185       4.3691290.379   3.5831    .141       3.7871177.451   3.2695    .023       2.0081169.846   3.2484    .046       1.6161158.939   3.2181    1.461      127.7821139.148   3.1631    .080       2.9741135.997   3.1544    .072       3.9881132.619   3.1450    .089       3.9911128.305   3.1330    .083       3.545995.594    2.7645    .081       3.409990.478    2.7503    .319       4.937965.625    2.6813    .247       9.342958.849    2.6625    .447       17.679952.251    2.6442    .191       8.417771.751    2.1430    .117       3.407765.016    2.1243    .241       6.467755.207    2.0970    1.509      59.872596.118    1.6553    .398       31.993594.078    1.6496    .324       31.181588.980    1.6354    .301       33.173586.888    1.6296    .366       31.940______________________________________ 
    
     IR(KBr, ν max , cm -1 ): 3430, 3300, 2920, 1720, 1640, 1560, 1510, 1450, 1330, 1220, 1060. 
     UV(MeOH, λ max , nm): 369, 220. 
     EXAMPLE 19 
     7-[2-(4-Pyridylmethyldithio)ethylamino]-9a-methoxymitosane (64).--Method A applied to 4-pyridylmethane thiol 
       1  H NMR data (pyridine d 5 ): 
     
         ______________________________________FREQUENCY       PPM     INTENSITY______________________________________3174.124        8.8137  1.5593086.504        8.5704  275.6812997.042        8.3220  1.7552751.614        7.6405  1.6212670.799        7.4161  152.5172619.866        7.2747  2.2152594.341        7.2038  13.4492588.514        7.1877  13.8872549.316        7.0788  10.6852538.735        7.0494  237.9662491.394        6.9180  1.6712476.552        6.8768  1.6262455.604        6.8186  1.8791997.041        5.2676  3.8961892.600        5.2553  3.9331886.432        5.2331  4.1611882.279        5.2266  3.3821778.252        4.9378  2.9471720.692        4.7779  50.8991650.169        4.5821  1.7791582.212        4.3934  6.6851569.373        4.3578  7.3941508.983        4.1901  1.5691461.935        4.0594  1.6081414.766        3.9285  1.6171394.661        3.8726  4.3291390.442        3.8609  4.9621383.398        3.8413  4.9191379.350        3.8301  4.3761364.298        3.7883  31.0001340.407        3.7220  3.8341333.778        3.7036  8.3471327.039        3.6849  8.2131320.566        3.6669  4.2871292.880        3.5900  1.7631246.523        3.4613  3.1721233.880        3.4262  2.9581179.559        3.2753  2.3211103.699        3.0647  60.4861077.339        2.9915  3.363963.663         2.6897  6.328961.933         2.6710  11.830955.266         2.6525  6.534934.417         2.5946  3.978336.539         2.3229  4.536334.326         2.3167  5.550832.030         2.3105  4.390699.151         1.9414  29.860487.633         1.3540  1.511332.357         .9229   1.611______________________________________ 
    
     IR(KBr, ν max , cm =1 ): 3440, 3290, 1720, 1640, 1605, 1560, 1515, 1450, 1330, 1065. 
     EXAMPLE 20 
     7-[2-(4-Methyl-2-pyridylmethyldithio)ethylamino]-9a-methoxymitosane (63).--Method A applied to 4-methyl-2-pyridylmethane thiol 
       1  H NMR data (pyridine d 5 ): 
     
         ______________________________________FREQUENCY       PPM     INTENSITY______________________________________3086.419        8.5702  239.1873011.849        8.3631  21.4493007.220        8.3503  22.2562671.331        7.4176  174.7802602.023        7.2252  20.5962594.621        7.2046  23.9152572.270        7.1425  11.1402565.754        7.1245  20.4052559.391        7.1068  11.8612539.018        7.0502  214.1052497.280        6.9343  23.5242492.564        6.9212  22.5102489.765        6.9135  20.5832484.914        6.9000  18.9601831.844        5.2532  14.6611887.614        5.2414  15.5621881.465        5.2244  17.0291877.276        5.2127  16.8211776.235        4.9322  6.8741725.906        4.7924  10.7661582.344        4.3938  30.8181569.610        4.3584  31.9701390.446        3.8609  17.5011386.216        3.8492  18.4601379.317        3.8300  17.7561375.091        3.8183  15.8611351.761        3.7535  14.7721345.005        3.7347  37.8381338.331        3.7162  38.3021331.673        3.6977  14.9071245.659        3.4589  10.5231238.513        3.4390  8.7681235.373        3.4303  8.4551102.135        3.0604  263.8491090.832        3.0290  3.8481074.317        2.9831  12.0331030.168        2.8605  1.861979.513         2.7199  26.621972.717         2.7010  45.298966.020         2.6824  23.341951.597         2.6423  2.822932.901         2.5904  14.404831.018         2.3075  2.380814.241         2.2609  23.991807.604         2.2425  11.000790.332         2.1946  2.335768.225         2.1332  202.142750.042         2.0827  2.241738.922         2.0518  2.803693.260         1.9250  11.444______________________________________ 
    
     EXAMPLE 21 
     7-[2-(4-Pyridyldithio)ethylamino]-9a-methoxymitosane (60).--Method A applied to 4-pyridine thiol 
       1  H NMR data (pyridine d 5 ): 
     
         ______________________________________FREQUENCY       PPM     INTENSITY______________________________________3086.649        8.5708  57.3233054.780        8.4824  1.6202671.319        7.4176  30.9342658.667        7.3824  2.3232653.425        7.3679  2.1512619.587        7.2739  .6402556.340        7.0997  2.4602539.166        7.0506  49.6651895.995        5.2647  .7791891.977        5.2535  .9541885.669        5.2360  1.1211881.501        5.2245  .9631790.914        4.9729  .6981779.668        4.9417  .8671769.467        4.9134  .6601719.407        4.7744  30.7631575.456        4.3746  1.4881562.781        4.3394  1.5671395.762        3.8757  1.2801391.530        3.8639  1.4781384.665        3.8449  1.4901380.365        3.8329  1.1491342.279        3.7272  1.4551335.741        3.7090  1.5051328.907        3.6900  .6521243.405        3.4526  1.2161230.856        3.4178  .6921108.243        3.0773  16.5291104.345        3.0665  3.0001080.133        2.9993  .8171043.465        2.8974  1.5601036.679        2.8786  2.5501030.071        2.8602  1.2881004.731        2.7899  .568934.708         2.5954  .885718.942         1.9963  1.440708.953         1.9686  .887676.425         1.8783  6.760______________________________________ 
    
     IR(KBr, ν max  cm -1 ): 3440, 3290, 2920, 1720, 1635, 1560, 1510, 1465, 1330, 1065. 
     UV(MeOH, ν max  nm): 219, 240.7, 368.4. 
     EXAMPLE 22 
     7-[2-(3-Methyl-2-imidazolylmethyldithio)ethylamino]-9a-methoxymitosane (59).--Method A applied to 3-methyl-2-imidazolylmethane thiol 
       1  H NMR data (pyridine d 5 ): 
     
         ______________________________________FREQUENCY       PPM     INTENSITY______________________________________3086.225        8.5697  122.1482670.664        7.4158  66.9412577.506        7.1571  2.0842570.864        7.1386  3.9852564.225        7.1202  2.6142538.717        7.0494  111.6902475.041        6.8726  12.5832474.081        6.8699  11.4171991.623        5.5302  7.5531894.038        5.2593  2.78321889.805        5.2475  2.9361883.545        5.2301  3.2921879.381        5.2186  3.1791773.734        4.9252  1.6161728.614        4.7999  40.3431581.458        4.3913  5.7711568.670        4.3558  6.6401475.622        4.0974  31.3321407.786        3.9091  2.3031390.174        3.8602  3.4041386.082        3.8488  3.8961378.969        3.8290  3.6131374.928        3.8178  3.1021336.207        3.7103  2.9491329.594        3.6919  7.7111322.960        3.6735  7.8601316.368        3.6552  2.8431243.997        3.4543  1.9891229.660        3.4145  5.6431220.716        3.3896  67.0941101.470        3.0585  53.3401073.712        2.9814  2.303963.590         2.6756  5.806956.921         2.6571  10.710950.380         2.6390  5.439931.156         2.5856  2.799836.039         2.3215  1.994833.802         2.3153  2.506831.678         2.3094  1.746732.551         2.0341  2.020703.377         1.9531  28.078______________________________________ 
    
     IR(KBr, ν max  cm -1 ): 3440, 3290, 2930, 1715, 1635, 1560, 1505, 1456, 1330, 1065. 
     UV(MeOH, λ max  nm): 221, 368, 570. 
     EXAMPLE 23 
     7-[2-(2-Amino-2-(ethoxycarbonyl)ethyldithio)ethylamino]-9a-methoxymitosane (40).--Method A applied to ethyl cysteinate 
       1  H NMR data (pyridine d 5 , δ): 1.16(t, 3H, J=8 Hz), 2.00(m, 1H), 2.08(s, 3H), 2.72(m, 1H), 3.00(m, 4H), 3.20(s, 3H), 3.56(bd, 1H, J=16 Hz), 3.72-4.12(m, 3H), 4.20(q, 2H, J=8 Hz), 4.52(d, 1H, J=16 Hz), 5.04(t, 1H, J=12 Hz), 5.36(dd, 1H, J=4, 12 Hz). 
     IR(KBr, ν max  cm -1 ): 3420, 3290, 2920, 1720, 1630, 1555, 1510, 1445, 1320, 1210, 1055. 
     UV(MeOH, λ max , nm): 220, 368. 
     EXAMPLE 24 
     7-[2-(2-Methoxycarbonyl)ethyldithio)ethylamino]-9a-methoxymitosane (32).--Method A applied to methyl 2-mercaptopropionate 
       1  H NMR data (pyridine d 5 ): 
     
         ______________________________________FREQUENCY       PPM      INTENSITY______________________________________3036.621        8.5708   52.9852685.541        7.4571   .9642671.420        7.4178   22.0112566.711        7.1271   1.7042560.323        7.1094   3.7092553.894        7.0915   2.4682539.174        7.0506   48.2441892.097        5.2539   2.4371887.915        5.2423   2.4081881.776        5.2252   3.0201877.563        5.2135   2.7421789.180        4.9681   1.3291778.437        4.9383   2.2801767.395        4.9076   1.2511714.709        4.7613   7.0321580.911        4.3898   5.1081568.144        4.3543   5.4361545.206        4.2906   7.5211538.974        4.2733   15.9361532.490        4.2553   9.0981393.162        3.8685   3.1501388.980        3.8568   3.1811381.922        3.3372   3.4601377.845        3.8259   2.8621368.102        3.7989   2.7241361.449        3.7804   6.9261354.697        3.7616   7.2251347.991        3.7430   2.9581244.836        3.4566   5.6531232.775        3.4231   2.0301104.313        3.0664   44.3261073.331        2.9943   2.0821038.407        2.8834   9.4281031.986        2.3656   15.9201025.699        2.8481   14.1261018.715        2.8287   10.6791011.898        1.8098   5.869934.910         2.5960   2.371713.368         1.9808   25.764667.709         1.8541   65.234______________________________________ 
    
     IR(KBr, ν max  cm -1 ): 3340, 3280, 2960, 1740, 1640, 1560, 1520, 1455, 1335, 1230, 1070. 
     UV(MeOH, λ max , nm): 368, 220. 
     EXAMPLE 25 
     7-[2-Dimethylaminoethyldithio)ethylamino]-9a-methoxymitosane (33).--Method A applied to 2-dimethylaminoethanethiol 
       1  H NMR data (pyridine d 5  δ): 1.98(s, 9H), 2.00 (bs, 1H), 2.42(m, 2H), 2.58(bs, 1H), 2.75(m, 4H), 2.99(bs, 1H), 3.06(s, 3H), 3.45(bs, 1H), 3.85(m, 3H), 4.39(dd, 1H, J=4, 10 Hz), 4.70(m, 1H), 5.23(dd, 1H, J=4, 10 Hz), 7.16(t, 1H). 
     EXAMPLE 26 
     7-[2-(2-Carboxyphenyldithio)ethylamino]-9a-methoxymitosane (34).--Method B applied to 2-mercaptobenzoic acid 
       1  H NMR data (pyridine d 5 ): 
     
         ______________________________________FREQUENCY       PPM      INTENSITY______________________________________3105.777        8.6240   1.0683095.623        8.5958   1.9953086.411        8.5702   81.4373071.395        8.5285   3.5873070.374        8.5257   3.7223063.973        8.5079   3.2073062.956        8.5051   3.2952971.028        8.2498   3.4222962.990        8.2275   3.6812689.885        7.4691   1.0382680.454        7.4429   1.5792670.359        7.4149   52.5222659.752        7.3855   3.0622651.257        7.3619   3.1932644.169        7.3422   1.8262569.382        7.1345   1.3722562.851        7.1164   4.3762555.595        7.0962   4.7212547.992        7.0751   3.4052583.284        7.0482   72.8981895.991        5.2647   1.8611891.918        5.2534   2.0991885.537        5.2357   2.4331881.409        5.2242   2.2631741.321        4.8352   6.0081574.703        4.3726   3.5321561.952        4.3371   3.9141394.094        3.8710   1.9951389.928        3.8595   2.2211383.040        3.8404   2.1211378.894        3.8288   1.9461334.928        3.7068   2.6011328.296        3.6883   2.7451244.108        3.4546   40.0351101.463        3.0585   29.4781066.231        2.9607   1.6521003.478        2.7864   2.733996.779         2.7678   5.468990.106         2.7493   2.776926.202         2.5718   1.893663.304         1.8418   20.960______________________________________ 
    
     EXAMPLE 27 
     7-[2-(4-Nitro-3-carboxyphenyldithio)ethylamino]-9a-methoxymitosane (35).--Method B applied to 5-mercapto-2-nitrobenzoic acid 
       1  H NMR data (pyridine d 5 ): 
     
         ______________________________________FREQUENCY       PPM      INTENSITY______________________________________3036.277        8.5698   570.7752943.307        3.1367   3.3272765.764        7.6798   5.7662757.565        7.6571   7.2102670.599        7.4156   284.3882533.303        7.0432   503.3041888.779        5.2447   4.8221884.614        5.2331   5.0071878.212        5.2153   5.8291874.120        5.2040   5.2661781.017        4.9454   6.8151770.174        4.9153   10.8911759.492        4.8857   7.7741733.376        4.8181   10.9731576.793        4.8784 7.3521564.168        4.3433   7.7671391.762        3.9646   6.3831387.619        3.8531   5.8941380.737        3.8340   6.4341376.590        3.8114   5.1321333.456        3.8224   6.5311329.266        3.6910   6.3281244.117        3.4546   8.5491232.499        3.4223   5.0611103.173        3.0632   77.7881062.837        2.9512   6.5161058.740        209899   6.8711013.064        2.8130   8.0541006.409        2.7945   14.156999.788         2.7762   6.715 -925.557 2.5700 6.602680.086         1.8884   48.400672.145         1.8664   8.733664.121         1.8441   155.478______________________________________ 
    
     IR(KBr, ν max , cm -1 ): 3440, 3280, 2930, 1605, 1620, 1640, 1560, 1510, 1455, 1340, 1065. 
     UV(H 2  O, λ max  nm): 220, 368. 
     EXAMPLE 28 
     7-[2-(2-Amino-2-carboxyethyldithio)ethylamino]-9a-methoxymitosane (36).--Method B is applied to cysteine. 
       1  H NMR data (D 2  O): 
     
         ______________________________________FREQUENCY       PPM      INTENSITY______________________________________1649.415        4.5800   3.1081645.021        4.5678   3.5521638.887        4.5508   4.0851634.273        4.5379   3.6641525.901        4.2370   2.3081515.309        4.2076   4.2401502.937        4.1733   4.0741489.072        4.1348   3.5151462.182        4.0601   5.4781458.281        4.0493   6.8651453.746        4.0367   11.8481447.340        4.0189   12.5141440.997        4.0013   6.5911312.694        3.6450   5.5671308.251        3.6327   7.6861302.226        3.6159   6.5191297.608        3.6031   5.7241196.176        3.3215   27.5501192.345        3.3108   4.9241181.395        3.2804   6.4971177.423        3.2694   6.9491168.542        3.2447   63.5941119.788        3.1094   6.2751111.126        3.0853   6.8671104.602        3.0672   5.8141096.139        3.0437   9.4011089.039        3.0240   9.4951083.236        3.0079   7.3981078.825        2.9956   10.0341072.130        2.9770   5.6381064.763        2.9566   3.050710.980         1.9742   52.332-13.126         -.0364   37.147______________________________________ 
    
     IR(KBr, ν max , cm -1 ): 3440, 3030, 2930, 1720, 1635, 1545, 1495, 1455, 1340, 1065. 
     UV(H 2  O, λ max  nm): 221, 286, 369. 
     EXAMPLE 29 
     7-[2-(δ-Glutamylamino)-2-(carboxymethylaminocarbonyl)ethyldithio)ethylamino]-9a-methoxymitosane (37).--Method B is applied to glutathione 
       1  H NMR data (D 2  O): 
     
         ______________________________________FREQUENCY       PPM      INTENSITY______________________________________1689.759        4.6920   2.0401685.239        4.6795   1.7771643.159        4.5626   3.8921639.038        4.5512   4.2141632.588        4.5333   4.7361628.077        4.5207   3.3021522.085        4.2264   4.1681511.609        4.1973   3.4901500.800        4.1673   11.2621487.527        4.1305   8.5441434.871        3.9843   6.3121429.119        3.9683   11.9421423.005        3.9513   6.0951360.220        3.7770   2.2241342.556        3.7279   15.7311337.863        3.7149   15.6041320.595        3.6669   2.9751307.367        3.6302   9.3771297.536        3.6029   5.6961293.109        3.5906   8.5311248.183        3.4659   1.8201222.128        3.3935   4.7771192.165        3.3103   1.5591165.228        3.2355   64.2951149.618        3.1922   5.4021145.417        3.1805   5.2241083.362        3.0082   9.8001070.734        2.9731   11.2741065.367        2.9582   11.0631060.328        2.9443   7.5671055.097        2.9297   7.8721041.201        2.8911   4.945905.486         2.5143   6.203897.491         2.4921   10.938890.187         2.4718   7.881763.565         2.1202   8.676756.686         2.1011   8.464702.759         1.9514   46.428675.381         1.8754   3.776614.279         1.7057   7.124-16.375         -.0455   71.146______________________________________ 
    
     EXAMPLE 30 
     7-[2-(2-Amino-2-((1-carboxy-3-methyl-1-butyl)aminocarbonyl)ethyldithio)ethylamino]-9a-methoxymitosane (38).--Method B is applied to L-cysteinyl(-L-)leucine 
       1  H NMR data (D 2  O): 
     
         ______________________________________FREQUENCY       PPM      INTENSITY______________________________________1651.506        4.5858   2.9241647.060        4.5734   3.1721640.615        4.5555   3.5301635.941        4.5426   3.1651534.085        4.2597   2.3201526.032        4.2374   3.9961515.102        4.2070   8.6681509.929        4.1927   7.3121502.857        4.1730   7.1991488.866        4.1342   4.8381448.667        4.0226   3.8161442.515        4.0055   7.0901436.264        3.9881   4.7731310.487        3.6389   5.8311296.868        3.6011   5.2431227.979        3.4098   2.9821209.376        3.3581   3.5561204.976        3.3459   3.3581197.754        3.3258   20.1611196.599        3.3226   19.8171190.217        3.3049   4.0001178.748        3.2731   2.3711171.258        3.2523   28.6541170.198        3.2493   25.8271147.478        3.1862   2.3281140.928        3.1681   2,3001112.099        3.0880   3.4401104.789        3.0677   3.8801090.655        3.0285   10.6251084.782        3.0121   7.076964.867         2.6792   2.187708.722         1.9679   21.305688.172         1.9109   2.286682.736         1.8958   2.129585.757         1.6265   4.378577.064         1.6024   9.258571.316         1.5864   10.734552.828         1.5351   2.644326.817         .9075    13.468321.984         .8941    19.288313.339         .8701    14.706 
    
     EXAMPLE 31 
     7-[2-(2-Carboxyethyldithio)ethylamino]-9a-methoxymitosane (49).--Method B applied to 2-mercaptopropionic acid 
       1  H NMR data (pyridine d 5 ): 
     
         ______________________________________FREQUENCY       PPM      INTENSITY______________________________________3173.918        8.8132   1.4823107.623        8.6291   1.703098.097        8.6026   2.9623086.067        8.5692   245.5562996.455        8.3204   1.7002750.459        7.6373   1.8822691.271        7.4730   2.0462682,509        7.4487   3.0992670.109        7.4142   179.8602618.587        7.2712   1.6912597.614        7.2129   2.0792591.598        7.1962   3.8792559.664        7.1075   1.9522550.756        7.0828   3.2492538.040        7.0475   223.1782455.884        6.8194   1.5641879.133        5.2179   2.4861874.974        5.2063   2.7321868.493        5.1883   3.0571864.431        5.1771   2.9161757.132        4.8791   2.3961746.322        4.8491   4.4931724.357        4.7881   12.7481578.370        4.3827   5.3601565.635        4.3474   5.8781383.183        3.8408   3.5581379.027        3.8292   3.8161372.105        3.8100   5.4161365.216        3.7909   6.1231358.754        3.7729   5.9741352.431        3.7554   2.6091244.376        3.4553   3.4401232.982        3.4237   2.7661154.455        3.2056   3.1981150.466        3.1946   3.9351147.759        3.1870   4.1171143.257        3.1745   8.2521136.033        3.1545   5.2351102.572        3.0616   41.9211059.477        2.9419   3.7001030.728        2.8621   4.9721024.210        2.8440   8.5201016.050        2.8213   6.9681008.250        2.7997   7.9481000.938        2.7794   3.981930.084         2.5826   3.740747.720         2.0762   1.353706.055         1.9605   30.939663.989         1.8437   86.533______________________________________ 
    
     EXAMPLE 32 
     7-[2-(4-Nitrophenyldithio)ethylamino]-9a-methoxy-1a-methylmitosane (41) 
     To a solution of 1a-methyl mitomycin A (98 mg, 0.28 mM (L. Cheng et al., J. Med. Chem. 20, 767 (1977)) in deoxygenated methanol (5 ml) was added at 0 deg. C. and under an argon atmosphere, p-nitrophenyldithioethylamine hydrochloride (81 mg) followed by addition of triethylamine (70 ul). The reaction mixture was allowed to warm up to room temperature and after 3.5 hrs. the reaction was almost complete as evidenced by thin layer chromatography (silica gel, 5% v/v MeOH in CH 2  Cl 2 ). The reaction mixture was concentrated under reduced pressure and the resulting residue chromatographed twice on silica gel using 5% v/v MeON in CH 2  Cl 2  to obtain the title compound pure, as a blue amorphous solid (68 mg, 43%). 
       1  H NMR data (pyridine d 5 ): 
     
         ______________________________________FREQUENCY       PPM      INTENSITY______________________________________3086.194        8.5696   7.3272909.668        8.0794   2.6972906.985        8.0720   15.6772900.119        8.0529   6.6442898.157        8.0474   19.4062728.645        7.5767   3.4232726.000        7.5694   19.6072724.024        7.5639   6.4192717.205        7.5450   17.5712714.433        7.5373   2.8112670.880        7.4163   3.9342592.925        7.1999   1.3632573.965        7.1472   2.3962567.475        7.1292   4.6782560.978        7.1112   2.4142538.815        7.0496   7.4651989.189        5.5235   17.2481869.362        5.1907   5.0281865.031        5.1787   5.1341859.039        5.1621   5.8651854.684        5.1500   5.4421713.379        4.7576   27.4821676.655        4.6556   5.4911665.804        4.6255   6.9421654.740        4.5948   4.7811546.359        4.2938   8.6761533.366        4.2578   9.5861378.895        3.8288   4.7031374.570        3.8168   5.1751367.615        3.7975   5.0901363.257        3.7854   4.8101360.238        3.7770   3.1271353.560        3.7585   7.7481346.877        3.7399   8.0541340.210        3.7214   3.0841217.740        3.3814   5.3831215.699        3.3757   5.7341204.960        3.3459   4.9051203.034        3.3405   4.5761108.963        3.0793   2.6131096.620        3.0450   64.2711063.680        2.9536   7.4561056.979        2.9350   14.7261050.296        2.9164   7.013858.399         2.3836   9.631853.826         2.3709   10.974758.850         2.1071   2.474753.017         2.0909   54.711738.462         2.0505   1.558723.515         2.0090   6.130721.571         2.0036   6.123719.009         1.9965   5.626717.087         1.9912   5.387675.259         1.8750   51.667531.663         1.4763   1.41737.518          .1042    2.929-57.316         -.1592   119.809-59.990         -.1666   6.098______________________________________ 
    
     IR(KBr, ν max , cm -1 ): 3460, 3300, 2950, 1755, 1640, 1560, 1515, 1455, 1430, 1415, 1330, 1225, 1060. 
     UV(MeOH, λ max , nm): 369 and 220. 
     EXAMPLE 33 
     7-[2-(3-Nitro-2-pyridyldithio)propylamino]-9a-methoxymitosane (44) 
     To a solution of 7-dimethylaminomethyleneamino-9a-methoxymitosane (744 mg, 1.91 mM) in deoxygenated methanol (12 ml) at about 0 deg. C. were added sequentially under stirring, 3-(4-nitro-phenyldithio)propylamine hydrochloride (1.55 g), prepared in the manor described in Ser. No. 581,291 from 3-mercaptopropylamine and employing the deBrois procedure using methoxycarbonylsulfenyl chloride, and triethylamine (774 ul). The reaction mixture was sonicated and allowed to stand at room temperature for 16 hours. Thin layer chromatography (silica gel, 10% MeOH in CH 2  Cl 2 ) revealed that a major faster blue component had been formed in addition to the presence of traces of starting material (green) and mitomycin C. The reaction mixture was concentrated under reduced pressure and the resulting residue was chromatograhed twice over silica gel using 5-10% v/v MeOH in CH 2  Cl 2  to obtain the title compound as the faster blue component, isolated as an amorphous blue solid. 
       1  H NMR data (pyridine d 5 ,) 
     
         ______________________________________FREQUENCY       PPM      INTENSITY______________________________________3146.622        8.7374   10.6563145.334        8.7338   12.1533142.191        8.7251   12.5583140.880        8.7214   12.8683098.074        8.6026   12.9883086.605        8.5707   368.7543007.372        8.3507   10.6092998.735        8.3267   11.6232997.529        8.3234   13.0042751.247        7.6395   2.9912682.257        7.4480   8.3582670.888        7.4164   158.6352619.438        7.2735   3.4862589.946        7.1916   15.5592585.500        7.1793   13.7432581.808        7.1690   13.8272577.322        7.1566   11.8182550.648        7.0825   13.3082538.876        7.0498   342.6552489.224        6.9119   7.2692456.328        6.8206   2.691879.962        5.2202   6.1521875.717        5.2084   6.1561869.761        5.1919   7.3411865.544        5.1801   6.8721783.865        4.9533   5.0261773.046        4.9233   8.1911762.088        4.8929   6.2401726.635        4.7944   152.0851587.007        4.4067   13.6591574.363        4.3716   14.2311386.003        3.8486   8.0391381.797        3.8369   8.8771374.826        3.8175   8.2851370.733        3.8062   7.3841295.122        3.5962   6.3111290.268        3.5828   13.3741283.643        3.5644   13.8451276.626        3.5449   6.6111247.654        3.4644   7.1551234.232        3.4272   6.3231174.396        3.2610   2.1081114.136        3.0937   3.0071103.806        3.0650   119.7001095.938        3.0431   4.2991078.188        2.9939   6.6411050.017        2.9156   15.7551042.930        2.8960   30.4691036.059        2.8769   16.193934.212         2.5941   6.742713.529         1.9813   58.234685.209         1.9027   5.453678.187         1.8832   14.115671.329         1.8641   19.760664.370         1.8448   13.086657.421         1.8255   4.108402.644         1.1180   1.812242.843         .6743    2.244235.548         .6541    1.981______________________________________ 
    
     EXAMPLE 34 
     7-[2-(4-Nitrophenyldithio)propylamino]-9a-methoxymitosane (45) 
     The title compound was prepared according to Method A using Compound No. 33 and 4-nitrothiophenol as reactants. 
       1  H NMR data (pyridine d 5 ): 
     
         ______________________________________FREQUENCY       PPM      INTENSITY______________________________________3086.648        8.5708   46.7002904.541        8.0651   3.1922895.707        8.0406   3.3552725.964        7.5693   3.9672717.144        7.5448   3.7202670.822        7.4162   19.7992538.767        7.0495   43.3572495.434        6.9292   .9241879.667        5.2193   .9491875.487        5.2077   .8801778.272        4.9378   .9071725.693        4.7918   11.8561588.217        4.4101   1.7021575.419        4.3745   1.8021391.549        3.8640   .9491387.471        3.8526   1.0121380.402        3.8330   .9941262.702        3.5062   .9361256.047        3.4877   2.1701249.302        3.4690   2.7341242.686        3.4506   1.1291236.092        3.4323   .8261104.391        3.0666   12.996986.877         2.7403   1.868979.734         2.7205   2.943972.546         2.7005   1.812937.074         2.6020   .832717.038         1.9910   .829697.821         1.9377   7.913665.479         1.8479   1.475658.432         1.8283   1.961651.446         1.8089   1.380______________________________________ 
    
     The results of antitumor evaluation of the above substances is summarized in the table which follows. The test data involves two experimental animal tumors, P-388 leukemia in mice and B16 melanoma in mice. In addition, the present substances were tested for cytotoxic activity in vitro. 
     The in vitro cytotoxicity assay involved growing various mammalian tumor cells, including human tumor cells, on microtitre plates employing established tissue culture methods. The concentration of each compound required to inhibit cell growth by 50% (IC 50 ) was then determined by a four-fold serial dilution technique. The validity of the method has been supported by a report published in the &#34;Proceedings of the American Association for Cancer Research&#34;, Vol. 25, 328, p. 1391 (1984). Tumor cells of one or more of the following types were employed for each compound tested: B16-F10 murine melanoma; C26 murine colon; Moser human colon; M109 murine lung; and RCA human colon. A wide range of IC 50  values was observed, but quantitative comparisons on the basis of these values were not made. The lowest IC 50  value, 0.66 mcg/ml, was observed with Compound 26341 against the B16-F10 murine melanoma. In that system mitomycin C exhibits IC 50  values in the range of 3-30 mcg/ml. Each of the claimed compounds was shown to be active (IC 50  &lt;500 mcg/ml). 
     P-388 Murine Leukemia 
     The test protocol involved CDF 1  female mice implanted intraperitoneally with a tumor inoculum of 10 6  ascites cells of P-388 murine leukemia and treated with various doses of a test compound, or with mitomycin C. The compounds were administered by intraperitoneal injection. Groups of six mice were used for each dosage amount and they were treated with a single dose of the compound on the day of inoculation. A group of ten saline treated control mice was included in each series of experiments. The mitomycin C treated groups were included as a positive control. A 30 day protocol was employed with the mean survival time in days being determined for each group of mice and the number of survivors at the end of the 30 day period being noted. The mice were weighed before treatment and again on day six. The change in weight was taken as a measure of drug toxicity. Mice weighing 20 grams each were employed and a loss in weight of up to approximately 2 grams was not considered excessive. The results were determined in terms of % T/C which is the ratio of the mean survival time of the treated group to the mean survival time of the saline treated control group times 100. The saline treated control animals usually died within nine days. The &#34;maximum effect&#34; in the table is expressed as % T/C and the dose giving that effect is reported. The values in parenthesis are the values obtained with mitomycin C as the positive control in the same experiment. Thus a measure of the relative activity of the present substances to mitomycin C can be estimated. A minimum effect in terms of % T/C was considered to be 125. The minimum effective dose reported in the following table is that dose giving a % T/C of approximately 125. The two values given in each instance in the &#34;average weight change&#34; column are respectively the average weight change per mouse at the maximum effective dose and at the minimum effective dose. 
     B16 Melanoma 
     BDF 1  mice were employed in the B16 melanoma test. They were inoculated subcutaneously with the tumor implant. A 60 day protocol was used. Groups of ten mice were used for each dosage amount tested and the mean survival time for each group was determined. For each dosage level, the test animals were treated with the test compound on days 1, 5, and 9 by the intravenous route. Control animals which had been inoculated in the same way as test animals and treated with the injection vehicle only containing no drug exhibited a mean survival time of 18.5 to 26 days. The survival time relative to that of the controls (% T/C) was used as a measure of effectiveness. A % T/C value of 140 or greater was considered significant tumor inhibition. The value shown in parenthesis is the % T/C for mitomycin C in the same experiment. Several of the compounds show antitumor effectiveness clearly superior to that of mitomycin C. Examples demonstrating the biggest difference in ratio of activity (% T/C compound/% T/C mitomycin C) are Compound Nos. 43, 56, and 60. 
     In view of the antitumor activity observed in experimental animal tumors, and the lack of undue toxicity as compared to mitomycin C, the invention includes use of the substances of the present invention for inhibiting mammalian tumors. For this purpose they are administered systematically to a mammal bearing a tumor in substantially non-toxic antitumor effective dose. 
     The compounds of the present invention are intended primarily for use by injection in much the same way and for some of the same purposes as mitomycin C. Somewhat larger or smaller doses may be employed depending upon the particular tumor sensitivity. They are readily distributed as dry pharmaceutical compositions containing diluents, buffers, stabilizers, solubilizers, and ingredients contributing to pharmaceutical elegance. These compositions are then constituted with an injectable liquid medium extemporaneously just prior to use. Suitable injectable liquids include water, isotonic saline, etc. 
     
         __________________________________________________________________________Antitumor Activity of Compounds of Formula IX(Alk.sub.2 is CH.sub.2 CH.sub.2, and R is H)                         B16 Melanoma                                  P-388 Murine Leukemia                         Optimal Effect       MinimumCompound Example                 (mouse i.v.)                                  Maximum Effect                                              Effect                                                   AverageNo. (BMY) Number      R.sup.9            Dose                             % T/C*                                  Dose*                                       % T/C* Dose Wt.__________________________________________________________________________                                                   Change32(26341) 24   CH.sub.3 CO.sub.2 CH.sub.2 CH.sub.2                                  6.4(3.2)                                       &gt;333(&gt;333)                                              &lt;0.2 +0.3, +1.633(26881) 25   (CH.sub.3).sub.2 NCH.sub.2 CH.sub.2                                  12.8(4.8)                                       167(172)                                              6.4  -1.2, -0.234(26678) 26       ##STR4##                   3.2(4.8)                                       150(195)                                              0.2  +0.5, +0.335(26712) 27       ##STR5##          6.4 147(124)                                  12.8(3.2)                                       322(233)                                              0.8  -0.6, +0.836(26711) 28       ##STR6##          6.4 163(124)                                  12.8(3.2)                                       306(233)                                              0.4  -1.8, +0.737(26733) 29       ##STR7##          9.6 179(142)                                  12.8(4.8)                                       144(239)                                              6.4  -0.1, +0.538(26880) 30       ##STR8##                   6.4(4.8)                                       167(172)                                              0.8  +0.7, +1.139(26187) 1       ##STR9##                   25.6(4.8)                                       233(233)                                              &lt;0.2 -1.9, +0.640(26190) 23       ##STR10##                  25.6(4.8)                                       283(233)                                              &lt;0.2 -0.9, +1.541(26339) 32       ##STR11##                  3.2(3.2)                                       167(&gt;333)                                              1.6  +1.2, +1.8      (R is methyl)42(26340) 17       ##STR12##         3.2 148(112)                                  12.8(3.2)                                       &gt;333(&gt;333)                                              &lt;0.2 -1.7, +1.743(26107) 15       ##STR13##         3.2 188(112) 211(145)                                  12.8(4.8)                                       &gt;333(&gt;333)                                              &lt;0.2 -4.5, +1.744(26495) 33       ##STR14##                  12,8(4.8)                                       200(275)                                              0.8  -1.2, +1.2      (Alk.sub.2 is CH.sub.2 CH.sub.2 CH.sub.2 -)45(26496) 34       ##STR15##                  25.6(4.8)                                       200(275)                                              1.6  0, +0.3      (Alk.sub.2 is CH.sub.2 CH.sub.2 CH.sub.2 )46(26646) 3       ##STR16##         2.4 206(153)                                  12.8(4.8)                                       186(195)                                              0.4  -0.3, +0.747(26650) 2       ##STR17##                  12.8(4.8)                                       182(195)                                              1.6  -0.4, +1.348(26112) 18       ##STR18##                  3.2(4.8)                                       167(&gt;333)                                              &lt;0.2 -2.0, +1.249(26679) 31   NaO.sub.2 CCH.sub.2 CH.sub.2                                  12.8(4.8)                                       191(195)                                              0.4  =0.8, +0.550(26681) 7       ##STR19##                  6.4(4.8)                                       173(195)                                              0.4  -0.4, +0.551(26682) 11       ##STR20##                  6.4(4.8)                                       182(195)                                              0.8  +0.3, -0.152(26683) 6       ##STR21##                  12.8(4.8)                                       168(195)                                              1.6  -0.8, +0.953(26702) 16       ##STR22##                  12.8(4.8)                                       105(195)                                              --   +1.0 --54(26708) 12       ##STR23##         1.6 216(149)                                  12.8(4.8)                                       222(233)                                              0.8  -0.3, +0.955(26709) 4       ##STR24##                  12.8(4.8)                                       183(233)                                              0.8  -0.2, +0.856(26713) 13       ##STR25##         1.6 251(149)                                  12.8(3.2)                                       250(233)                                              0.4  -2.9, +0.957(26715) 9       ##STR26##         4.8 209(153)                                  12.8(3.2)                                       194(233)                                              0.2  -0.7, +1.458(26716) 8       ##STR27##         6.4 209(153)                                  12.8(3.2)                                       211(233)                                              0.1  -0.2, +1.359(26723) 22       ##STR28##         4.8 4.8                             226(179) 187(142)                                  12.8(4.8)                                       322(239)                                              6.4  -2.0, -0.860(26731) 21       ##STR29##         9.6 251(149)                                  12.8(4.8)                                       256(239)                                              3.2  -1.9, +0.261 (26732) 10       ##STR30##                  12.8(4.8)                                       150(239)                                              3.2  -1.3, +3.262(26857) 14       ##STR31##                  12.8(4.8)                                       139(239)                                              12.8 +0.6, +0.663(26858) 20       ##STR32##                  6.4(4.8)                                       144(239)                                              1.6  -1.7, +0.564(26861) 19       ##STR33##         3.2 173(149)                                  6.4(4.8)                                       183(239)                                              1.6  -2.1, +0.865(26879) 5       ##STR34##                  3.2(4.8)                                       178(172)                                              0.8  +0.4,__________________________________________________________________________                                                   +0.5