Abstract:
Disclosed is an anti-tumor liposoluble platinum (IV) complexes having Formula I, a Formula VI or a Formula XII. Because these complexes have liposoluble groups, they are effective for various internal organ tumors or cancers. ##STR1##

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to a novel anti-tumor platinum (IV) complex which may be liposoluble. 
     A certain kind of a platinum complex has been known to have an anti-tumor function, and such platinum complexes have been reported and been practically used. While, especially, a cis-dichlorodiammine platinum (II) complex (general name: cisplatine) and carboplatine are employed mainly for a spermary cancer, an ovarium cancer, a vesica cancer, a lung cancer and a cervix cancer, a platinum complex effective for the other organ tumors (for example, a brain tumor) other than the above cancers has seldom been reported. A platinum complex having a high specificity to a certain organ is desired. 
     Among the platinum complexes, a platinum (IV) complex of an isomer having a formula of PtCl 4  -dach (&#34;dach&#34; designates cyclohexanediamine) has been expected to have new possibilities and reported U.S. Pat. No. 4,599,352, European Patent Publications Nos. 43490/77, 156659/78 and 13888/78, British Patent Publication Nos. 8328218 and 8028484). 
     However, all of these complexes are chlorinated ones, and they are not necessarily satisfactory in connection with the anti-tumor function in internal organs. No complexes other than chlorinated ones have been reported and their anti-tumor functions are unknown. 
     SUMMARY OF THE INVENTION 
     Accordingly, an object of the present invention is to provide a novel anti-tumor platinum complex which possesses more excellent anti-tumor characteristics than a conventional one, especially effective for internal organ tumors. 
     Another object of the present invention is to provide a novel anti-tumor platinum complex which may perorally administrated. 
     The liposoluble platinum (IV) complex of the present invention is, as mentioned later, excellent in anti-tumor characteristics, and because the complex is liposoluble, it is remarkably useful for recovering internal organ cancers in addition to the spermary cancer and the like. 
     Some of the complexes of the present invention have one or more liposoluble groups, for example, a carboxylic group having a long carbon chain, on its Z-axis to be more active against tumors. 
     It is pointed out that an anti-tumor complex which is effective for the internal organ cancers, especially for the brain tumor is required to have a high liposolubility. Because of the above liposoluble group, the complex of the present invention is considerably effective for various tumors or cancers. 
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention is an anti-tumor liposoluble halogenated platinum (IV) complex having a Formula I. In this Formula I, --A--A-- designates one of the diamines of 1,2-cycloalkanediamine having a Formula II [n in the Formula II is 1, 2, 3 or 4, and its steric configuration is cis(R,S-), trans-d(1S,2S-) or trans-1(1R,2R-)], 2-aminomethylcyclohexylamine having a Formula III [in this Formula, its steric configuration is cis-1(R,R-), cis-d-(S,S-), trans-1(R,S-) or trans-d(S,R-)], 1,1-diaminomethylcyclohexane having a Formula IV, o-phenylenediamine, ethylenediamine and propyrenediamine, and X designates bromine, iodine or fluorine. The preferred diamine is 1,2-cyclohexanediamine having a Formula V. ##STR2## 
     Another aspect of the present invention is a novel anti-tumor liposoluble platinum (IV) complex having a Formula VI. In this Formula VI, the symbol --A--A-- has the same meanings as those of the Formula I, and the symbol --L--L-- in the Formula VI designates a ligand forming a five or six-membered ring coordinating the platinum (IV) in the form of --O--O-- coordination, and X designates one of carboxylate, carbonate, carbamate, sulfate and phosphate. The --L--L-- is preferably oxalate having a Formula VII, 1,1-cyclobutane-dicaroxylate having a Formula VIII, a malonate having a Formula IX, a glycolate having a Formula X, a malonate derivative having a Formula XI or a glycolate derivative having a Formula XII. ##STR3## 
     A further aspect of the present invention is a novel anti-tumor liposoluble platinum (IV) complex having a Formula XII. In this Formula XII, the symbol --A--A-- has the same meanings as those of the Formula I, X designates bromine, iodine or fluorine, and B 1  and B 2  designate a ligand forming a five or six-membered ring coordinating the platinum (IV) in the form of --O--O-- coordination. 
    
    
     EXAMPLES 
     Although the present invention will be described more in detail referring to Example, these Examples are not construed to restrict the present invention. 
     EXAMPLE 1 
     Synthesis of tetrabromo-1-dach-platinum (IV) complex (Formula XIV) ##STR4## 
     In 15 ml of ion exchange water, 1.50 g of dihydroxo-oxalato-1-dach-platinum (IV) complex (Formula XV) (3.48 mmol) was suspended. To this suspension, 3 ml of hydrobromic acid (47%) was added at 75° C. and reacted for 85 minutes. After 5 ml of water was further added to this suspension, which was then cooled at room temperature, a green precipitate was obtained upon filtration which was then washed with water. After the precipitate was dissolved in acetone for filtration of impurities, the filtrate was concentrated under vacuum to which hexane was added. The orange precipitate thus formed was collected by means of filtration and washed with hexane to obtain 0.65 g (30%) of tetrabromo-1-dach-platinum (IV) complex. 
     EXAMPLE 2 
     Synthesis of tetrabromo-d-dach-platinum (IV) complex (Formula XVI) 
     After 1.18 g (2.52 mmol) of dibromo-d-dach-platinum (II) complex (Formula XVI) was suspended in 67 ml of methanol, about 20 ml of a bromine-methanol solution (0.25 mmol/ml) was added at room temperature. After the lapse of one hour, the insoluble substances were removed by filtration and the filtrate was concentrated under vacuum. A crystal was collected by cooling the concentrated solution to 5° C. and filtrating the solution, and the crystal thus produced was washed with ether to obtain 1.07 g (88%) of tetrabromo-d-dach-platinum (IV) complex. 
     EXAMPLE 3 
     Synthesis of tetrabromo-cis-dach-platinum (IV) complex (Formula XVI) ##STR5## 
     After 0.90 g of dibromo-cis-dach-platinum (II) (Formula XVI, 1.92 mmol) was suspended in 10 ml of methanol, 10 ml of a bromine (0.32 g, 2.0 mmol)-methanol solution was added to the suspension at room temperature. After the lapse of 90 minutes, orange precipitate produced was filtrated and washed with water. After the filtrated substance was dissolved in N,N-dimethyl formamide (DMF) to which small amounts of methanol and water were added, the solution was allowed to stand for two days. After a large amount of water was added, the orange precipitate was collected by means of filtration and washed with water to obtain 0.32 g (26%) of tetrabromo-cis-dach-platinum (IV) complex. 
     EXAMPLE 4 
     Synthesis of tetraiodo-1-dach-platinum (IV) complex (Formula XVII) 
     After 2.00 g (4.64 mmol) of dihydroxo-oxalato-1-dach-platinum (IV) (Formula XV) was suspended in 30 ml of ion exchange water, 4 ml of hydroiodic acid (57%) was added to this suspension without irradiation of lights at 70° C. and allowed to react for one hour. After the cooling to 5° C., the precipitate was collected by filtration and washed with water. After drying, 3.40 g (90° C.) of tetraiodo-1-dach-platinum (IV) complex was obtained. 
     EXAMPLE 5 
     Synthesis of tetraiodo-d-dach-platinum (IV) complex (Formula XVII) ##STR6## 
     The same procedures as those of Example 4 were performed except that dihydroxo-oxalato-d-dach-platinum (IV) was employed in place of the dihydroxo-oxalato-1-dach-platinum (IV) of Example 4, to obtain 0.78 g (82%) of a tetraiodo-d-dach-platinum (IV) complex. 
     EXAMPLE 6 
     Synthesis of tetraiodo-cis-dach-platinum (IV) complex (Formula XVIII) 
     The same procedures as those of Example 4 were performed except that dihydroxo-oxalato-cis-dach-platinum (IV) was employed in place of the dihydroxo-oxalato-1-dach-platinum (IV) of Example 4, to obtain 0.79 g (83%) of a tetraiodo-cis-dach-platinum (IV) complex. 
     Elementary analysis and infrared absorption analysis of the compound synthesized in Examples 1 to 6 were carried out. The results thereof were shown in Tables 1 and 2. All of the said compounds were highly liposoluble. 
     
                       TABLE 1______________________________________Ex-am-  Molecular Formula              Theoretical Value                           Measured Valueple  (Molecular Weight)              H      C    N    H    C    N______________________________________1    C.sub.6 H.sub.14 Br.sub.4 N.sub.2 Pt(628.89)              2.24   11.46                          4.45 2.32 11.75                                         4.432    &#34;             &#34;      &#34;    &#34;    2.29 11.49                                         4.193    &#34;             &#34;      &#34;    &#34;    2.42 11.63                                         4.504    C.sub.6 H.sub.14 I.sub.4 N.sub.2 Pt(816.89)              1.73    8.82                          3.43 2.00 8.94 3.395    &#34;             &#34;      &#34;    &#34;    1.99 9.07 3.266    &#34;             &#34;      &#34;    &#34;    1.88 9.08 3.51______________________________________ 
    
     
                       TABLE 2______________________________________Example     1      2       3    4     5    6______________________________________IR(cm-1) of N--H       3160   3170    3175 3185  3180 3165______________________________________ 
    
     Anti-tumor properties of the complexes of Examples 1 to 6 against L1210, an experimental tumor of a mouse, were examined. 
     After L1210 (the number of implanted cells was 10 5  per mouse) was transplanted in a CDF 1  mouse, the above complexes were administrated in its abdominal cavity at a first day, a fifth day and a ninth day. 
     The evaluation was determined by means of an average survival period propagation rate T/C (%) [(average survival days of administrated group)/(average survival days of reference group)×100]. For L1210, 125 or more is deemed effective, and the results thereof are shown in Table 3. One group consisted of six mice. The numbers in the brackets in Table 3 exhibits the numbers of the mice recovered. 
     
                       TABLE 3______________________________________Ex-  Average Surviving Period Propagation Rate T/C (%)am-  [Administration Dose (mg/Kg)]ple  400    200    100  50   25    12.5  6.25 3.12  1.56______________________________________1                             0    235(1)                                    2502                            182(1)                              182(1)                                    1323                            163(1)                              202(2)                                    1114                  141  121  1115           107    109  1056           111    109   90______________________________________ 
    
     EXAMPLE 7 
     Synthesis of dibromo-oxalato-1-dach-platinum (Formula XVIII) ##STR7## 
     To 5.00 g (11.6 mmol) of dihydroxo-oxalato-1-dach-platinum (Formula XIX), 50 ml of ion exchange water and 4.41 g (23.2 mmol) of p-toluenesulfonic acid monohydrate were added at room temperature. After the mixture was shaken for completely dissolving the dihydroxo-oxalato-1-dach-platinum, the reaction solution was concentrated under vacuum and dried up. To this, 100 ml of ethanol was added and then 2.78 g (23.2 mmol) of potassium bromide was added at 5° C. and stirred for one hour. After the lapse of 80 minutes, a yellow precipitate was collected by filtration and dried with ion exchange water until the pH of the filtrate became neutral. The precipitate was further washed with ethyl acetate to obtain 2.98 g (43%) of dibromo-oxalato-1-dach-platinum as its dihydrate. 
     EXAMPLE 8 
     Synthesis of dibromo-oxalato-d-dach-platinum (Formula XX) ##STR8## 
     In 10 ml of ion exchange water was suspended 1.00 g (2.52 mmol) of oxalato-d-dach-platinum (Formula XX). To this suspension was added 10 ml of bromine water (0.26 mmol/ml) at 5° C. which was then vigorously shaken for 100 minutes. After the temperature was returned to room temperature, the reaction was kept to be continued for another 20 minutes and then again cooled to 5° C. After a yellow precipitate was collected by filtration and washed with water, the precipitate was dissolved in methanol for separating insoluble substances by filtration. When 30 ml of ion exchange water was added to the filtrate which was then concentrated under vacuum, a crystal begins to be formed, which was cooled to 5° C., was allowed to stand. The crystal was collected by filtration, and washed with water and dried to prepare 1.13 g (76%) of dibromo-oxalato-d-dach-platinum as its dihydrated compound. 
     EXAMPLE 9 
     Synthesis of diiodo-oxalato-1-dach-platinum (Formula XXI) 
     In 10 ml (2.52 mmol) of N,N-dimethetylformamide was suspended 1.00 g (2.52 mmol) of oxalato-1-dach-platinum (Formula XX), and 0.640 g (2.52 mmol) of iodine was added thereto at 70° C. After the lapse of about one hour, 10 ml of DMF was added to the above solution and insoluble substances were filtered. A crystal was collected by filtration upon addition of ethyl acetate to the filtrate, and the crystal was washed with ethyl acetate to obtain 1.52 g (76%) of diiodo-oxalato-1-dach-platinum. However, every two DMFs were contained in the respective molecules. 
     EXAMPLE 10 
     Synthesis of diiodo-oxalato-d-dach-platinum (Formula XXI) ##STR9## 
     The same procedures as those of Example 9 were performed except that oxalato-d-dach-platinum was employed in place of the oxalato-1-dach-platinum of Example 9, to obtain 1.55 g (77%) of diiodo-oxalato-1-dach-platinum. 
     EXAMPLE 11 
     Synthesis of dibromo-malonate-1-dach-platinum (Formula XXII) 
     In 10 ml of water was suspended 1.167 g (2.837 mmol) of malonate-1-dach-platinum (Formula XXII) to which 10 ml (2.88 mmol) of bromine water was added and thereafter vigorously agitated. After the lapse of 10 minutes, a yellow precipitate was collected by filtration and washed with water. The precipitate was dissolved in DMF for separating insoluble substances by filtration, and ethyl acetate was added thereto. The crystal produced was collected by filtration, and washed with ethyl acetate to obtain 0.42 g (25%) of dibromo-malonate-1-dach-platinum as its monohydrated compound. ##STR10## 
     EXAMPLE 12 
     Synthesis of dibromo-malonate-d-dach-platinum (Formula XXIV) 
     The same procedures as those of Example 11 were performed except that malonate-d-dach-platinum was employed in place of the malonate-1-dach-platinum of Example 11, to obtain 0.92 g (53%) of dibromo-malonate-d-dach-platinum. 
     Elementary analysis and infrared absorption analysis of the compound synthesized in Examples 7 to 12 were carried out. The results thereof were shown in Tables 4 and 5, respectively. All of the said compounds were highly lipsoluble. 
     
                                           TABLE 4__________________________________________________________________________Molecular Formula  Theoretical Value                        Measured Value (%)Example(Molecular Weight)              H  C  N (%)                        H  C   N__________________________________________________________________________7    C.sub.8 H.sub.14 Br.sub.2 N.sub.2 O.sub.4 Pt.2H.sub.2 O(593.13)              3.06                 16.20                    4.72                        3.14                           16.25                               4.748    &#34;             &#34;  &#34;  &#34;   3.16                           16.24                               4.519    C.sub.8 H.sub.14 I.sub.2 N.sub.2 O.sub.4 Pt.2DMF(797.29)              3.54                 21.09                    7.03                        3.66                           21.06                               6.6510   &#34;             &#34;  &#34;  &#34;   3.51                           20.51                               6.7411   C.sub.9 H.sub.16 Br.sub.2 N.sub.2 O.sub.4 Pt.H.sub.2 O(589.14)              3.08                 18.35                    4.75                        3.00                           18.49                               4.5912   &#34;             &#34;  &#34;  &#34;   3.17                           18.23                               4.75__________________________________________________________________________ 
    
     
                       TABLE 5______________________________________Example     7      8       9    10    11   12______________________________________IR(cm.sup.-1) of N--H       3175   3170    3045 3045  3180 3180IR(cm.sup.-1) of C═O       1710   1715    1715 1715  1660 1655______________________________________ 
    
     Anti-tumor properties of the complexes of Examples 7 to 12 against L1210, an experimental tumor of a mouse, were examined. 
     After L1210 (the number of implanted cells was 10 5  per mouse) was transplanted in a CDF 1  mouse, the above complexes were administered in its abdominal cavity at a first day, a fifth day and a ninth day. 
     The evaluation was determined by means of an average survival period propagation rate T/C (%) [(average survival days of administrated group)/(average survival days of reference group)×100]. For L1210, 125 or more is deemed effective, and the results thereof are shown in Table G. One group consisted of six mice. The numbers in the brackets in Table 6 exhibits the numbers of the mice recovered. 
     
                       TABLE 6______________________________________Ex-  Average Surviving Period Propagation Rate T/C (%)am-  [Administration Dose (mg/Kg)]ple  400    200    100  50    25    12.5 6.25 3.12 1.56______________________________________7                  T92  263(3)                         288(3)8                       175   132   1349           91     105  201(1)                         27310           0     T194 13411                      247   209   13112                      228(1)                         185   176______________________________________ 
    
     EXAMPLE 13 
     Synthesis of Pt (oxalato)(OCOCH 3 ) 2  (1-dach) (Formula XXIV) 
     To 5.00 g (11.6 mmol) of Pt(oxalato)(OH) 2  (1-dach) was added 50 ml (510 mmol) of acetic anhydride, which was then agitated at 70° C. for three hours. Thereafter, the reaction solution was concentrated and eventually dried up under vacuum. ##STR11## 
     Then, the dry residue was recrystallized from 60 ml of hot water to obtain 4.12 g (69%) of Pt(oxalato)(OCOCH 3 ) 2  (1-dach). 
     EXAMPLE 14 
     Synthesis of Pt(oxalato)(OCOCH 2  CH 3 ) 2  (1-dach) (Formula XXV) 
     To 4.00 g of Pt(oxalato)(OH) 2  (1-dach) was added 40 ml of propionic anhydride, which was then agitated at 75° C. for 25 hours. After the solution was cooled to room temperature by standing, 250 ml of hexane was added to the solution, and a precipitate was collected by filtration. After the precipitate was washed with hexane and dissolved in methanol, insoluble substances were filtered and the filtrate was concentrated under vacuum. 
     Then, the residue was recrystallized from methanol-diethylether-petroleum ether to obtain 3.79 g (75%) of Pt(oxalato)(OCOCH 2  CH 3 ) 2  -(1-dach). ##STR12## 
     EXAMPLE 15 
     Synthesis of Pt(oxalato)[OCO(CH 2  CH 2  CH 3  ] 2  (1-dach) (Formula XXVI) 
     To 7.00 g of Pt(oxalato)(OH) 2  (1-dach) was added 70 ml of n-butyric anhydride. Thereafter, the same procedures as those of Example 14 were performed to obtain 5.47 g (57%) of Pt(oxalato)[OCO(CH 2 ) 2  CH 3  ] 3  (1-dach) as its monohydrate. ##STR13## 
     EXAMPLE 16 
     Synthesis of Pt(oxalato)[OCO(CH 2 ) 3  Ch 3  ] 2  (1-dach) (Formula XXVI) 
     To 1.00 g of Pt(oxalato)(OH) 2  (1-dach) were added 5 of DMF and 5 ml of n-pentanoic anhydride, which were then agitated at 75° C. for 24 hours. After the solution was concentrated under vacuum, a large amount of hexane was added to the residue. 
     After the precipitate was collected by filtration and washed with hexane, it was isolated with a silica gel column chromatography (eluent: ethyl acetate). The isolated precipitated was recrystallized from methanol-diethylether to obtain 0.49 g (34%) of Pt(oxalato)-[OCO(CH 2 ) 3  CH 3  ] 2  (1-dach) as its monohydrate. ##STR14## 
     EXAMPLE 17 
     Synthesis of Pt(oxalato)[OCO(CH 2 ) 4  CH 3  ] 2  (1-dach) (Formula XXVI) 
     In accordance with the same procedures as those of Example 16 except that n-hexanoic anhydride and 10 ml of DMF were employed in place of the n-pentanoic anhydride and 5 ml of DMF, 0.83 g (57%) of Pt(oxalato)[OCO(CH 2 ) 4  CH 3  ] 2  (1-dach) was obtained. ##STR15## 
     EXAMPLE 18 
     Synthesis of Pt(oxalato)[OCO(CH 2 ) 5  CH 3  ] 2  (1-dach) (Formula XXIX) 
     In accordance with the same procedures as those of Example 16 except that 6 ml of n-heptanoic anhydride and 10 ml of DMF were employed in place of the n-pentanoic anhydride and 5 ml of DMF, 0.98 g (64%) of Pt(oxalato)[OCO(CH 2 ) 5  CH 3  ] 2  (1-dach) was obtained as its 1/2 hydrate. ##STR16## 
     EXAMPLE 19 
     Synthesis of Pt(oxalato)[OCO(CH 3 ) 6  CH 3  ] 2  (1-dach) (Formula XXX) 
     In accordance with the same procedures as those of Example 16 except that 6 ml of n-octanoic anhydride and 10 ml of DMF were employed in place of the n-pentanoic anhydride and 5 ml of DMF, 1.16 g (73%) of Pt(oxalato)[OCO(CH 2 ) 5  CH 3  ] 2  (1-dach) was obtained. ##STR17## 
     EXAMPLE 20 
     Synthesis of Pt(malonato) (OCOCH 3 ) 2  (1-dach) (Formula XXXI) 
     To 1.00 g of Pt(malonato)(OH) 2  (1-dach) was added 10 ml of acetic anhydride, which was then agitated at 70° C. for two hours and twenty minutes. After the solution was cooled to room temperature, a large amount of diethylether was added to cool the temperature to 5° C. The precipitate was collected by filtration and washed with ether. After the precipitate was dissolved in water and insoluble substances were filtered, the filtrate was concentrated under vacuum. 
     Then, the residue was recrystallized from methanol-water-diethylether to obtain 0.93 g (78%) of Pt(malonato)(OCOCH 3 ) 2  (1-dach). ##STR18## 
     EXAMPLE 21 
     Synthesis of Pt(malonato)(OCOCH 2  CH 2 ) 2  (1-dach) (Formula XXXII) 
     In accordance with the same procedures as those of Example 14 except that 300 mg of Pt(malonato)(OH) 2  (1-dach), 3 ml of propionic anhydride and 3 ml of toluene as a solvent were employed in place of the 4.00 g of Pt(oxalato)(OH) 2  (1-dach) and 40 ml of propionic anhydride, 351 mg (86%) of Pt(malonato)(OCOCH 2  CH 3 ) 2  (1-dach) was obtained as its 5/2 hydrate. ##STR19## 
     EXAMPLE 22 
     Synthesis of Pt(malonato)[OCO(CH 3 ) 2  CH 3  ] 2  (1-dach) (Formula XXXII) 
     In accordance with the same procedures as those of Example 14 except that 1.00 g of Pt(malonato)(OH) 2  (1-dach), 10 ml of n-butyric anhydride and 10 ml of toluene as a solvent were employed in place of the 4.00 g of Pt(oxalato)(OH) 2  (1-dach) and 40 ml of propionic anhydride, 0.37 g (28%) of Pt(malonato)[OCO(CH 3 ) 2  CH 3  ] 2  (1-dach) was obtained as its 1/2 hydrate. ##STR20## 
     EXAMPLE 23 
     Synthesis of Pt(malonato)[OCO(CH 2 ) 3  CH 3  ] 2  (1-dach) (Formula XXXII) 
     In accordance with the same procedures as those of Example 16 except that 1.00 g of Pt(malonato)(OH) 2  (1-dach), 5 ml of n-pentanoic anhydride and 10 ml of toluene as a solvent were employed in place of the 1.00 g of Pt(oxalato)(OH) 2  (1-dach), 5 ml of DMF and 5 ml of n-pentanoic anhydride 0.35 g (25%) of Pt(malonato)[OCO(CH 2 ) 2  CH 3  ] 2  (1-dach) was obtained. ##STR21## 
     EXAMPLE 24 
     Synthesis of Pt(malonato)[OCO(CH 2 ) 4  CH 3  ] 2  (1-dach) (Formula XXXV) 
     In accordance with the same procedures as those of Example 16 except that 1.00 g of Pt(malonato)(OH) 2  (1-dach), 5.5 ml of n-hexanoic anhydride and 10 ml of toluene as a solvent were employed in place of the 1.00 g of Pt(oxalato)(OH) 2  (1-dach), 5 ml of DMF and 5 ml of n-pentanoic anhydride, 0.86 g (59%) of Pt(malonato)[OCO(CH 2 ) 4  CH 3  ] 2  (1-dach) was obtained as its 1/2 hydrate. ##STR22## 
     EXAMPLE 25 
     Synthesis of Pt(malonato)[OCO(CH 2 ) 5  CH 3  ] 2  (1-dach) (Formula XXXVI) 
     In accordance with the same procedures as those of Example 16 except that 1.00 g of Pt(malonato)(OH) 2  (1-dach), 4.5 ml of n-heptanoic anhydride and 10 ml of toluene as a solvent were employed in place of the 1.00 g of Pt(oxalato)(OH) 2  (1-dach), 5 ml of DMF and 5 ml of n-pentanoic anhydride, 0.69 g (45%) of Pt(malonato)[OCO(CH 2 ) 5  CH 3  ] 2  (1-dach) was obtained as its 1/2 hydrate. ##STR23## 
     EXAMPLE 26 
     Synthesis of Pt(malonato)[OCO(CH 2 ) 6  CH 3  ] 2  (1-dach) (Formula XXXVII) 
     To 1.00 g of Pt(malonato)(OH) 2  (1-dach) were added 10 ml of toluene and 5 ml of n-octanoic anhydride, which were then agitated at 75° C. for about 18 hours. After the toluene was distilled off, 10 ml of DMF was added to the residue and agitated at 75° C. for 1.5 hours. 
     Then, the DMF was distilled off and hexane was added to the residue which was then cooled to about -50° C. The precipitate was collected and isolated with a silica gel column chromatography (eluent, ethyl acetate:hexane =3:1). Thereafter, it was precipitated at about -70° C. from ethyl acetate-hexane to obtain 0.72 g (44%) of Pt(malonato)[OCO(CH 2 ) 6  CH 3  ] 2  (1-dach) in which 1/4 molecule of the hexane was incorporated per one molecule of the platinum complex. ##STR24## 
     The analytical data of the compounds (complexes) prepared in Examples 13 to 26 are shown in Tables 7 and 8. 
     
                                           TABLE 7__________________________________________________________________________Molecular Formula   Theoretical Value                         Measured Value (%)Example(Molecular Weight)               H  C  N (%)                         H  C   N__________________________________________________________________________13   C.sub.12 H.sub.20 N.sub.2 O.sub.8 Pt(515.38)               3.91                  27.97                     5.54                         4.53                            27.80                                5.3714   C.sub.14 H.sub.24 N.sub.2 O.sub.8 Pt(543.43)               4.46                  30.94                     5.16                         4.64                            31.10                                5.2615   C.sub.16 H.sub.28 N.sub.2 O.sub.5 Pt.H.sub.2 O(589.50)               5.13                  32.60                     4.75                         4.93                            32.39                                4.7616   C.sub.18 H.sub.22 N.sub.2 O.sub.6 Pt.H.sub.2 O(617.56)               5.55                  35.01                     4.54                         5.49                            35.30                                4.6617   C.sub.20 H.sub.30 N.sub.2 O.sub.8 Pt(627.58)               5.78                  38.28                     4.46                         5.99                            38.13                                4.4818   C.sub.22 H.sub.40 N.sub.2 O.sub.8.1/2H.sub.2 O(664.66)               6.22                  39.76                     4.21                         6.32                            39.77                                4.2519   C.sub.24 H.sub.44 N.sub.2 O.sub.8 Pt(683.70)               6.49                  42.16                     4.10                         6.79                            42.19                                4.0020   C.sub.18 H.sub.22 N.sub.2 O.sub.8 Pt(529.41)               4.19                  29.49                     5.29                         3.90                            27.42                                4.9621   C.sub.16 H.sub.20 N.sub.2 O.sub.8 Pt.5/2H.sub.2 O(602.50)               5.19                  29.90                     4.65                         4.95                            29.75                                4.7122   C.sub.17 H.sub.30 N.sub.2 O.sub.8 Pt.1/2H.sub.2 O(594.52)               5.26                  34.34                     4.71                         6.25                            34.53                                4.8723   C.sub.19 H.sub.34 N.sub.2 O.sub.8 Pt(613.57)               5.59                  37.19                     4.57                         5.68                            37.11                                4.6024   C.sub.21 H.sub.42 N.sub.2 O.sub.8 Pt.1/2H.sub.2 O(650.63)               6.04                  38.77                     4.30                         6.21                            38.85                                4.3725   C.sub.23 H.sub.42 N.sub.2 O.sub.8 Pt.1/2H.sub.2 O(678.68)               6.39                  40.70                     4.13                         6.54                            40.90                                4.1226   C.sub.26 H.sub.48 N.sub.2 O.sub.8 Pt.1/4C.sub.6 H.sub.14 (719.27)               6.94                  44.25                     3.89                         6.94                            44.25                                3.89__________________________________________________________________________ 
    
     
                       TABLE 8______________________________________        IR (cm.sup.-1)Example        N--H        C═O______________________________________13             3030        1725, 166014             3155        1720, 169015             3200        173016             3150        172517             3190        173018             3160        178019             3130        173020             3180        1680, 165021             3150        165022             3050        1680, 165023             3050        1680, 164024             3100        168025             3100        169026             3050        1670, 1640______________________________________ 
    
     Anti-tumor properties of the complexes of Examples 13 to 26 against L1210, an experimental tumor of a mouse, were examined. 
     After L1210 (the number of implanted cells was 10 5  per mouse) was transplanted in a CDF 1  mouse, the above complexes were administrated in its abdominal cavity at a first day, a fifth day and a ninth day. 
     The evaluation was determined by means of an average survival period propagation rate T/C (%) [(average survival days of administrated group)/(average survival days of reference group)×100]. For L1210, 125 or more is deemed effective, and the results thereof are shown in Table 9. One group consisted of six mice. The numbers in the brackets in Table 9 exhibits the numbers of the mice recovered. 
     
                                           TABLE 9__________________________________________________________________________Average Surviving Period Propagation Rate T/C (%)[Administration Dose (mg/Kg)]Example 400    200 100 50  25  12.5                       6.25                          3.12                             1.56__________________________________________________________________________13           214(1)            214 125 117                        9814           220 230(1)                150 138                       11715           160(1)            271(2)                221 15616       112 309(2)            297(3)17       166 286(3)            214(1)18       130 207(1)            225(1)19       150 112 11620       227(1)        140 141 103 10921       241(1)        187 137 132 12222       207 174 13223       144 130 11424        0  122 10625       108 114 11226       137 110 112__________________________________________________________________________