Abstract:
14-Aminodaunomycins, which are prepared by reacting 14-bromodaunomycin with an amine in a solvent at about 20°-60° C. are useful in treating certain tumors such as ascites Sarcoma 180 and solid Sarcoma 180.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to novel daunomycin derivatives, processes for their preparation and the use thereof. 
     2. Description of the Prior Art 
     Daunomycin and Adriamycin are known antitumor glycoside antibiotics respectively described and claimed in British Pat. Nos. 1,033,383 and 1,161,278 and 1,217,133, all of which are owned by the unrecorded assignee hereof. The starting material for the preparation of the novel compounds of this invention, 14-bromodaunomycin, in a known compound and can be obtained according to the procedures described in said British Pat. No. 1,217,133. 
     SUMMARY OF THE INVENTION 
     The novel daunomycin derivatives of the invention are the 14-amino derivatives having the general formula I, and pharmaceutically acceptable acid addition salts thereof: ##STR1## wherein R and R&#39; are independently selected from the group consisting of hydrogen, lower alkyl, hydroxy lower alkyl, dihalo lower alkyl, amino lower alkyl and (lower alkyl amino) lower alkyl, with the proviso that R and R&#39; are not both hydrogen and wherein R and R&#39;, together with the nitrogen atom to which they are bound, may form a heterocyclic ring, optionally containing a further hetero atom in addition to the nitrogen atom shown in formula I. Examples of such heterocyclic rings are piperidino, pyrrolidino, morpholino, piperazino, lower alkyl-piperazino, hydroxy lower alkyl-piperazino and halo lower alkyl-piperazino. 
     As used herein the term &#34;lower alkyl&#34; means straight and branched chain alkyl groups containing up to 4 carbon atoms. 
     The invention also provides processes for the preparation of the above-described daunomycin derivatives and their acid addition salts. The process comprises reacting 14-bromodaunomycin, which has the general formula II: ##STR2## or an acid addition salt thereof, with the appropriate primary or secondary amine of the formula NHRR&#39;, wherein R and R&#39; are as defined above in an organic solvent, such as acetone or t-butanol, at a temperature of about 20° C. to 60° C., and, if desired, acidifying the resulting product to obtain the acid addition salt. The novel daunomycin derivatives of the invention are useful in the treatment of certain neoplastic diseases as will be described in more detail below. Their antitumor activity is as effective as that of daunomycin, but they display a much lower toxicity than daunomycin. 
     BIOLOGICAL ACTIVITY 
     The biological activity of the compounds of the invention, in terms of both in vitro and in vivo activity, will now be described. 
     In vitro studies 
     Mouse embryo fibroblasts (MEF) were plated on 35 mm. Falcon plastic dishes and infected 24 hours later with Moloney Sarcoma Virus (MSV) in the presence of DEAE-dextran (25 μg./ml.). The samples were then treated for 3 days with different concentrations of the compounds of the invention. The number of foci of transformed cells was microscopically determined 5 days after the infection. Uninfected MEF were similarly treated and at the end of the experiment, the cells were counted in an haemocytometer. In all the experiments, the cells were incubated in a 5% CO 2  incubator at 37° C. 
     For use in these tests the compounds were dissolved in distilled water or in 5% ethyl alcohol in distilled water and then diluted in culture medium. 
     The results of these tests are reported in Table I in terms of ID 50  values (Inhibiting Dose 50%), calculated on dose-effects lines. 
     In vivo studies 
     The antitumor activity of the compounds of the invention was tested on ascites Sarcoma 180. 
     Three month old CD 1 mice were used. Sarcoma 180 ascites cells were inoculated intraperitoneally (10 6  cells/mouse). For use in these tests, the compounds were dissolved in distilled water or in 5% ethyl alcohol in distilled water, then diluted with Ringers solution and administered i.p. 1 day after the tumor implant (10 ml./kg. of body weight). 
     The toxicity of the test compounds was evaluated by macroscopic autoptic examination mainly in terms of reduction in spleen size. The comparison of the effectiveness of the test compounds is based on the maximum increase in median survival time, as compared to untreated controls, over the dose range used. The number of Long Term Survivors (LTS) refers to tumor-free mice at the end of the experiment (60 days). The effect observed on ascites Sarcoma 180 is reported in Table II. Solid Sarcoma 180 was implanted subcutaneously by trocar in the flank of CD 1 mice according to standard methods. The mice were treated i.v. for 5 consecutive days, starting 1 day after the tumor implant. On the 11th day the tumor volume was measured by means of a caliper and evaluated according to the formula (a 2  × b)/2, a and b being the minimum and the maximum diameters respectively. The results are reported in Table III. 
     
                                           TABLE I__________________________________________________________________________In Vitro Activity On MSV-M Foci Formation And On MEF*Proliferation__________________________________________________________________________             MSV-M        MEF*       Dose  No. of foci                    ID 50 No. of cells                                 ID 50Compound    (μg/ml.)             %      (μg/ml.)                          %      (μg./ml.)__________________________________________________________________________Daunomycin  0.0250             0            22       0.0125             17     0.006 45     0.0086       0.0062             51           55Adriamycin  0.0250             0            37       0.0125             24     0.005 42     0.01       0.0062             46           6114-(N-morpholino)-       0.4   0            21daunomycin  0.1   17     0.032 31     0.5       0.0250             69           68       0.0062             78           8114-[N-(N&#39;-methyl)-       0.4   0            23piperazino]-daunomycin       0.1   19     0.011 56     0.09       0.0250             35           64       0.0062             60           6714-(N-piperidino)-       0.4   0            24daunomycin  0.1   42     0.08  58     0.1       0.0250             89           71       0.0062             100          8714-(N-(N&#39;-hydroxyethyl)-       0.4   2            31piperazino]-daunomycin       0.1   43     0.045 52     0.08       0.0250             64           64       0.0062             71           6714-diethanol-amino-       0.4   0            25daunomycin  0.1   21     0.052 56     0.13       0.0250             73           95       0.0062             75           100__________________________________________________________________________ *Mouse Embryo Fibroblasts 
    
     
                                           TABLE II__________________________________________________________________________ Activity On Ascites Sarcoma 180__________________________________________________________________________                                     %         Dose  T/C.sup.(1)                          %    Toxic.sup.(3)                                     ToxicCompound      (mg./kg.)               %     LTS.sup.(2)                          LTS  Deaths                                     Deaths__________________________________________________________________________Daunomycin    0.2   106   1/20 5    0/20  0         1     193   9/20 45   0/20  0         5     173   3/20 15   3/20  15Adriamycin    0.2   148   5/30 16   0/30  0         1     177   13/29                          45   0/29  0         5     200   9/47 19   5/47  10         10    156   0/10 0    2/10  2014-(N-morpholino)-         0.2   103   0/10 0    0/10  0daunomycin    1     111   0/10 0    0/10  0         5     133   3/10 30   0/10  0         25    223   5/17 29   0/17  0         50    100   0/7  0    1/7   14         100   50    1/7  14   6/7   8514-[N-(N&#39;-methyl)-         0.2   119   0/10 0    0/10  0piperazino]-daunomycin         1     103   0/10 0    0/10  0         5     116   0/10 0    0/10  0         12.5  167   3/10 30   1/10  10         25    226   3/10 30   0/10  0         50    130   1/10 10   5/10  5014-(N-piperidino)-         0.2   103   0/10 0    0/10  0daunomycin    1     100   0/10 0    0/10  0         5     140   2/10 20   0/10  0         12.5  200   2/10 20   0/10  0         25    218   2/10 20   0/10  0         50    144   2/10 20   4/10  4014-[N-(N&#39;-hydroxyethyl)-         0.2   103   0/10 0    0/10  0piperazino]-daunomycin         1     103   0/10 0    0/10  0         5     103   1/10 10   0/10  0         12.5  152   0/10 0    0/10  0         25    222   1/10 10   0/10  0         50    152   0/10 0    3/10  3014-diethanolamino         0.2   106   0/10 0    0/10  0daunomycin    1     103   0/10 0    0/10  0         5     124   0/10 0    0/10  0         12.5  181   0/10 0    0/10  0         25    187   4/20 20   0/20  0         50    175   4/17 23   0/17  0         75    170   0/10 0    1/10  10         100   83    0/7  0    3/7   42         200   25    0/7  0    7/7   100__________________________________________________________________________ .sup.(1) Median survival time, % over untreated controls .sup.(2) Long Term Survivors after 60 days .sup.(3) Number of mice which died as a result of the toxic effect of the compound 
    
     
                       TABLE III______________________________________ Activity On Solid Sarcoma 180______________________________________        Dose      Tumor Volume.sup.(1)                                ToxicCompound     (mg./kg.) T/C %         Deaths______________________________________14-(N-morpholine)-        3         77            0/10daunomycin   4         64            0/10        5         69            0/1014-diethanolamino-        12.5      82            1/5daunomycin   25        66            1/5        50        44            0/5______________________________________ .sup.(1) % T/C tumor weight index at 11th day 
    
     RESULTS 
     The activity of the compounds investigated in comparison with the present compounds confirms the fact that modifications in the acetyl side chain in the 9-position of the saturated ring of daunomycin can lead to noticeable modifications in the biological activity. The 14-aminodaunomycins investigated were found to be less active than daunomycin in in vitro tests, but less toxic than daunomycin and adriamycin in mice, the optimal dose being between 12.5 and 25 mg./kg. (1 single treatment i.p. at day 1 after tumor implant), in comparison with optimal doses of 1 or 5 mg./kg. for daunomycin and adriamycin. 
     The optimal doses resulted in an increase of the life span of mice infected with ascites Sarcoma 180 of about 100%, after a single treatment. It is important to note that with the present compounds, good antitumor effects can be achieved with doses considerably lower than the LD 10 . 
     On solid Sarcoma 180, the results reported in Table III, show that 14-diethanolaminodaunomycin exerted a marked inhibition of tumor growth, at non-toxic doses. 
     All the results therefore, strongly suggest that the introduction of a basic group in the side chain of daunomycin leads to marked increases in the antitumor activity, at the optimal dose, in comparison with daunomycin. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The invention will now be described in more detail in the following preparative examples. All parts given are by weight unless otherwise indicated. 
     EXAMPLE 1 
     14-(N-morpholino)-daunomycin 
     To a suspension of 2 grams of 14-bromodaunomycin hydrobromide in 70 ml. of acetone, 2 ml. of morpholine were added and the solution was maintained at 50° C. for 2 hours. 
     After removal of the solvent in vacuo, the residue was taken up in 100 ml. of water which was then extracted with four 100 ml. portions of chloroform. The combined chloroform extracts were evaporated under reduced pressure to form a residue which was then dissolved in 20 ml. of methanol, and one equivalent of 0.1 N methanolic HCl was added. 1.6 g. of 14-(N-morpholino)-daunomycin monohydrochloride were precipitated by the addition of diethyl ether; E 1 .2 = 1.7; E 1  cm. 1%  = 190 at 495 nm. 
     EXAMPLE 2 
     14-[N-(N&#39;-methyl)-piperazino]-daunomycin 
     To a suspension of 4 grams of 14-bromodaunomycin hydrobromide in 200 ml. of acetone, 4 ml. of N-methylpiperazine were added and the solution was maintained at 50° C. for 4 hours. 
     After removal of the solvent in vacuo, the residue was taken up in 100 ml. of water and extracted with four 100 ml. portions of chloroform. The combined chloroform extracts were then evaporated under reduced pressure to give a residue which was dissolved in 20 ml. of methanol. To the resulting solution was added one equivalent of 0.1 N methanolic HCl. Diethyl ether was then added to precipitate 3 grams of crude 14-[N-(N&#39;-methyl)piperazino]-daunomycin which were then dissolved in 100 ml. of water. The pH of the solution was adjusted to 7 with sodium bicarbonate and the solution was extracted with chloroform. 
     To the aqueous phase, NaHCO 3  was again added until the pH reached 8.2, and then the solution was repeatedly extracted with chloroform. 
     The combined chloroform extracts were evaporated off under reduced pressure to yield a residue which was dissolved in 10 ml. of methanol. To the methanol solution was added one equivalent of 0.1 N methanolic HCl. 2.0 g. of 14-[N-(N&#39;-methyl)-piperazino]-daunomycin hydrochloride were precipitated with diethyl ether; E 1 .2 = 2; E 1  cm. 1%  = 182 at 495 nm. 
     EXAMPLE 3 
     14-(N-piperidino)-daunomycin 
     By following the procedures described in Example 1, but using an equivalent amount of piperidine instead of morpholine, 14-(N-piperidino)-daunomycin monohydrochloride was obtained; E 1 .2 = 1.7; E 1  cm. 1%  = 192 at 495 nm. (yield = 65%). 
     EXAMPLE 4 
     14-(N-pyrrolidino)-daunomycin 
     By following the procedures described in Example 1, but using an equivalent amount of pyrrolidine instead of morpholine, 14-(N-pyrrolidino)-daunomycin monohydrochloride was obtained; E 1 .2 = 1.72; E 1  cm. 1%  = 202 at 495 nm. (yield = 66%). 
     EXAMPLE 5 
     14-diethylaminodaunomycin 
     By following the procedures described in Example 1, but using; an equivalent amount of diethylamine instead of morpholine, 14-diethylaminodaunomycin monohydrochloride was obtained; E 1 .2 = 1.72; E 1  cm. 1%  = 205 at 495 nm. (yield = 63%). 
     EXAMPLE 6 
     14-bis-chloroethylaminodaunomycin 
     By following the procedures described in Example 1, but using an equivalent amount of bis-chloroethylamine instead of morpholine, 14-bis-chloroethylaminodaunomycin monohydrochloride was obtained; E 1 .2 = 1.69, E 1  cm. 1%  = 180 at 495 nm. (yield = 68%). 
     EXAMPLE 7 
     14-[N-(N&#39;-hydroxyethyl)piperazino]-daunomycin 
     By following the procedures described in Example 2, but using an equivalent amount of N-hydroxyethyl-piperazine as the amine, 14-[N-(N&#39;-hydroxyethyl)piperazino]-daunomycin monohydrochloride was obtained; E 1 .2 = 1.98; E 1  cm. 1%  = 178 at 495 nm. (yield = 53%). 
     EXAMPLE 8 
     14-diethanolaminodaunomycin 
     By following the procedures described in Example 2, but using an equivalent amount of diethanolamine instead of N-methyl-piperazine, 14-diethanolaminodaunomycin monohydrochloride was obtained; E 1 .2 = 1.7; E 1  cm. 1%  = 188 at 495 nm. (yield = 42%). 
     EXAMPLE 9 
     14-(β-diethylamino)-ethylamino-daunomycin 
     By following the procedures described in Example 2, but using an equivalent amount of β-diethylaminoethylamine instead of the N-methyl-piperazine, 14-(β-diethylamino)ethylamino-daunomycin monohydrochloride was obtained; E 1 .2 = 2.0; E 1  cm. 1%  = 180 at 495 nm. (yield = 45%). 
     Other compounds of the general formula I can also be conveniently prepared by following the above-described techniques and substituting the appropriate amine. 
     Variations and modifications can, of course, be made without departing from the spirit and scope of the invention.