Chiral 1,5-diiodo-2-methoxy or benzyloxy intermediates

Abstract: Morpholinyl derivatives of doxorubicin having the general formula A: wherein X represents a linear or branched C₁-c₆ alkyl group or a benzyl group -CH₂C₆H₅, and having (S) or (R) configuration at carbon atom C-2" of the morpholino ring, are antitumor agents.

Description: The invention provides new chiral intermediates of general formula C wherein X represents a methyl group or a benzyl residue -CH 2 C 6 H 5 . The compounds which may have a (S) or (R) configuration at carbon atom C-2" of the morpholino ring are useful intermediates for preparing anthracycline glycoside antibiotics. The invention provides a process for the preparation of optically pure diiodo compounds C , starting from sugar precursors such as the compound of general formula S derived from L-arabinose: wherein X is as defined above. This process comprises: (a) subjecting to periodate oxidation a compound of formula S · : wherein X is as defined above; (b) reducing the thus-obtained dialdehyde derivative of formula D·· : wherein X is as defined above; (c) sulfonating the thus-obtained dihydroxy derivative of formula E· : wherein X is as defined above; and (d) iodinating the sulfonated derivative thus obtained. In order to prepare the diiodo compounds C , 1-substituted sugars S · , prepared following standard procedures described in "Methods on Carbohydrate Chemistry" Acad. Press., Vol 1, (1962), are first transformed into dialdehyde derivatives D · . Generally, D- or L-arabinose is employed as a starting material. This is reacted with an alcohol X-OH thereby to form the compound of formula S·· . The dialdehyde derivatives can be obtained by using periodate oxidation in water, then reduced to 1,5-dihydroxy-2-alkoxy or -benzyloxy-3-oxa-pentane E · by using reducing agents such as sodium borohydride or sodium cyanoborohydride at pH 6.5 in a mixture of water and methanol. The resultant dihydro compounds E · are sulfonated at the 1- and 5-hydroxyl groups, typically by using p-toluensulfonyl chloride in pyridine at 4°C to give the sulfonyl esters of formula F · from which the diiodo derivatives C are obtained upon treatment with sodium or potassium iodide in aprotic solvent such as methylethylketone at 85°C from one to two days. The sequence of these reactions do not affect the chirality at C-2 of the diiodo derivatives C which is the same of the starting sugars S . A preferred embodiment of a process according to the invention is illustrated by the following reaction Scheme: Reaction Scheme The following Examples illustrate the invention. Example 1 Preparation of 1, 5-di(p-toluensulphonyl),oxy-2(s)-benzyloxy-3-oxa-pentane (F1) L-arabinose (3 g, 0.022 mole) and benzyl alcohol (15 ml) were heated under stirring in presence of Dowex 50Wx2 (2 g) in acidic form. After four hours, the mixture was cooled and filtered. The solvent was removed under reduced pressure and l-benzyl-β-L-arabinopyranoside ( S1 , 3.5 g) was recovered from acetone. TLC on Kieselgel Plate F 254 (Merck), eluting system methylene chloride/methanol/water (120/20/2 by volume) Rur: Rf=0.47. [α] D =+215° (c=1% water). 1-benzyl-β-L-arabinopyranoside ( S1 , 3.48 g, 0.0145 mole) was dissolved in water (100 ml) and treated with sodium periodate (5.6 g, 0.026 mole) at 0°C for two hours. Then barium chloride was added and the mixture was brought to pH 7 with barium carbonate, filtered off and washed with water. The aqueous solution was concentrated under reduced pressure to a syrup and extracted with acetonitrile (50 ml). The organic phase was diluted with a mixture of methanol (20 ml) and water (10 ml) and treated with sodium cyanoborohydride (0.3 g) dissolved in water (5 ml). After 15 minutes the mixture was brought to pH 7 by adding Dowex 50Wx2 and filtered. The solvents were removed under reduced pressure to give 1,5-dihydroxy-2(S)-benzyloxy-3-oxa-pentane ( E1 ., 2.6g, yield 85%). TLC on Kieselgel Plate-F 254 (Merck), eluting system methylene chloride/methanol (10/1 by volume) Rur: Rf=0.28. Compound E1 (2.6 g) was dissolved in dry pyridine and added with p-toluensulfonylchloride (6.67 g). The mixture was kept at 0°C overnight, then poured into ice-water and extracted with methylene chloride. The organic phase was washed with water, separated off, dryied over anhydrous sodium sulphate and filtered off. The solvent was removed under reduced pressure to afford 1,5-di(p-toluensulphonyl)oxy-2(S)-benzyloxy-3-oxa-pentane ( F1 , 4.3 g, yield 68%). TLC on Kieselgel Plate F 254 (Merck), eluting system methylene chloride/acetone (98/2 by volume) R f =0.55 1 HNMR (CDCl 3 , 400 MHz) δ: 2.42 (s, 6H, two CH 3 Ts); 3.65, 3.69 (two dt, J=4.7, 11.7Hz, 2H, TsOCH 2 CH 2 O); 3.94 (two, dd, J=5.3, 10.5Hz, 2H, OCH- CH 2 -OTs); 4.08 (t, J=4.7Hz, 2H, Ts-O- CH 2 CH 2 -O); 4.46, 4.56 (two, d, J=11.7Hz, 2H, O CH 2 -Ph); 4.72 (t, J=5.3Hz, 1H, O- CH -CH 2 -OTs); 7.2-7.8 (m, 13H, aromatics). Example 2 Preparation of 1,5-diiodo-2(S)-benzyloxy-3-oxa-pentane ( C1 ). Compound F1 (4.3 g, 8.3 mmole), prepared as described in Example 1, was dissolved in methylethylketone (50 ml) and added with sodium iodide (7.4 g, 49 mmole). The mixture was kept at 95°C for twentyfour hours. After that, the solvent was removed under reduced pressure and the residue was extracted with n-hexane. The organic phase was concentrated to a syrup to give the title compound C1 (3.5 g, yield 90%). TLC on Kieselgel Plate F 254 (Merck), eluting system n-hexane/ethyl acetate (10/0.5 by volume) R f =0.34 1 HNMR (CDCl 3 , 400 MHz) δ : 3.27 (t, J=6.8Hz, 2H, J- CH 2 CH 2 -O); 3.30 (d, J=5.5Hz, 2H, O-CH- CH 2 -J); 3.84 (m, 2H, J-CH 2 , CH 2 -O); 4.63, 4.74 (two d, J=11.7Hz, 2H, O- CH 2 Ph); 4.81 (t, J=5.5Hz, 1H, O- CH -CH 2 -J); 7.3-7.5 (m, 5H, aromatics). Example 3 Preparation of 3'-deamino-3'[2(s)-benzyloxy-4-morpholinyl] doxorubicin ( A1 ) To a solution of doxorubicin hydrochloride (0.5 g, 0.86 mmole) in dry dimethylformamide (20 ml) was added 1,5-diiodo-2(S)-benzyloxy-3-oxa-pentane ( C1 , 3.5 g, 7.54 mmole) and dry triethylamine (3.6 ml, 2.6 mmole). The mixture was kept at room temperature for 36 hours, then was poured in water and extracted with methylene chloride. After standard work-up, the crude product was purified on silicic acid column using as eluting system a mixture of methylene chloride/methanol (97/5 by volume), to give, after treatment with methanolic anhydrous hydrogen chloride, the title compound A1 (0.3 g, yield 46%) as hydrochloride salt. TLC on Kieselgel Plate F 254 (Merck), eluting system methylene chloride/methanol (10/1 by volume) R f =0.6. FD-MS: m/e 756 (M+) 1 HNMR of free base (CDCl 3 , 200 MHz) δ: 1.37 (d, J=6.6Hz, 3H, 5'- CH 3 ); 1.76 (m, 2H, 2'- CH 2 ); 2.14 (dd, J=3.9, 14.8Hz, 1H, 8ax- H ); 2.2-2.7 (m, 6H, CH 2 -N- CH 2 , 8eq- H , 3'- H ); 3.00 (d, J=18.8Hz, 1H, 10ax- H ); 3.55, 4.00 (two m, 2H, O- CH 2 CH 2 N); 3.68 (s, 1H, 4'- H ); 3.94 (q, J=6.6Hz, 1H, 5'- H ); 4.08 (s, 3H, O CH 3 ); 4.51, 4.77( two d, J=12.1Hz, 2H, OCH 2 Ph); 4.65 (dd, J=2.6, 4.0Hz, 1H, O CH (OCH 2 Ph)CH 2 N); 4.71 (s, 1H, CO CH 2 OH); 5.28 (dd, J=2.4, 3.8Hz, 1H, 7-H); 5.54 (m, 1H, 1'- H ); 7.2-8.1 (m, 8H, aromatic H's); 13.22 (s, 1H, 11- OH ); 13.95 (s, 1H, 6- OH ). Example 4 Preparation of 1,5-diiodo-2(S)-ethoxy-3-oxa-pentane ( C2 ). The title compound C2 was prepared starting from L-arabinose (3 g) following sequential reactions as described in Example 1 and Example 2. 1-ethyl-α-L-arabinopyranoside ( S2 ): [α] D = +233.5° (c=1% water 1,5-dihydroxy-2(S)-ethoxy-3-oxa-pentane ( E2 ): TLC on Kieselgel Plate F 254 (Merck) eluting system methylene chloride/methanol (10/1 by volume) R f =0.33. 1,5-di(p-toluensulphonyl)oxy-2(S)-ethoxy-3-oxa-pentane ( F2 ): TLC on Kieselgel Plate F 254 (Merck), eluting system methylene chloride/acetone (98/2 by volume) R f =0.56 1 HNMR (CDCl 3 , 200MHz) δ: 1.11 (t, J=7.0Hz, 3H, OCH 2 CH 3 ); 2.43 (s, 6H, two CH 3 -Ts); 3.44, 3.58 (two dq, J=7.0, 9.4Hz, 2H, O CH 2 CH 3 ); 3.68 (m, 2H, O-CH 2 - CH 2 -OTs); 3.89 (d, J=5.4, 2H, O-CH- CH 2 -OTs); 4.10 (t, J=4.8Hz, 2H, OCH 2 - CH 2 OTs); 4.61 (t, J=5.4Hz, 1H, O- CH -CH 2 OTs); 7.3-7.8 (m, 8H, aromatic H's). 1,5-diiodo-2(S)-ethoxy-3-oxa-pentane ( C2 ): TLC on Kieselgel Plate F 254 (Merck), eluting system n-hexane/ethyl acetate (10/0.5 by volume) R f =0.37 1 HNMR (CDCl 3 , 200MHz) δ: 1.24 (t, 7.0Hz, 3H, OCH 2 CH 3 ); 3.23 (d, J=5.6Hz, 2H, J- CH 2 CH-O); 3.27 (t, J=6.8Hz, 2H, J- CH 2 CH 2 -O); 3.58, 3.77 (two dq, J=7.0, 9.3Hz, 2H, O CH 2 CH 3 ); 3.78, 3.87 (two dt, J=6.8, 10.6Hz, 2H, J-CH 2 CH 2 -O); 4.70 (t, J=5.6Hz, 1H, O- CH -CH 2 -J). Example 5 Preparation of 3'-deamino-3'[2(S)-ethoxy-4-morpholinyl] doxorubicin ( A2 ) Doxorubicin hydrochloride (0.5 g) was reacted with compound C2 (3 g) following the same procedure reported in Example 3 to give the title compound A2 (0.28 g) as hydrochloride salt. TLC on Kieselgel Plate F 254 (Merck), eluting system methylene chloride/methanol (10/1 by volume) R f =0.58 FD-MS: m/e 694 (M+) 1 HNMR as free base (CDCl 3 , 200MHz) δ: 1.16 (t,J=7.0Hz, 3H, OCH 2 , CH 3 ); 1.36 (d, J=6.4Hz, 3H, 5'- CH 3 ); 1.7-1.8 (m, 2H, 2'- CH 2 ,); 2.16 (dd, J=4.1, 14.7Hz, 1H, 8ax- H ); 2.3-2.6 (m, 6H, CH 2 ,-N- CH 2 );, 8eq- H , 3'- H ); 3.02 (d, J=18.8Hz, 1H, 10ax- H ); 3.26 (dd, 1.9, 18.8Hz, 1H, 10eq- H ); 3.46, 3.75 (two dq, J=7.0, 9.8Hz, 2H, O CH 2 CH 3 ); 3.53, 3.93 (two m, 2H, O CH 2 CH 2 ,N); 3.68 (s, 1H, 4'- H ); 3.93 (q, J=6.4Hz, 1H, 5'- H ); 4.08 (s, 3H, O CH 3 ); 4.56 (dd, J=2.3, 4.7Hz, 1H, O CH (OCH 2 CH 3 )CH 2 N); 4.72 (s, 1H, 9- OH ); 4.74 (s, 2H, CO CH 2 OH); 5.30 (m, 1H, 7- H ); 5.55 (m, 1H, 1'- H ); 7.3-8.1 (m, 3H, aromatic H's); 13.25 (s, 1H, 11- OH ); 13.97 (s, 1H, 6- OH ) Example 6 Preparation of 1-5-diiodo-2(R)-isopropyloxy-3-oxa-pentane ( C3 ) The title compound C3 was prepared starting from L-arabinose (3 g) following sequential reactions as described in Example 1 and Example 2. 1-isopropyl-β-L-arabinopyranoside ( S3 ): [α] D = +225° (water) 1,5-dihydroxy-2(R)-isopropyloxy-3-oxa-pentane ( E3 ): TLC on Kieselgel Plate F 254 (Merck), eluting system methylene chloride/methanol (10/1 by volume) R f =0.36 1,5-di(p-toluensulphonyl)oxy-2(R)-isopropyloxy-3-oxa-pentane ( F3 ) TLC on Kieselgel Plate F 254 (Merck), eluting system methylene chloride/acetone (95/2 by volume) R f =0.55 1 HNMR (CDCl 3 , 200MHz) δ: 1.05, 1.10 (two d, J=6.2Hz, 6H, CH( CH 3 ) 2 ); 2.42 two s, 6H, CH 3 -Ts); 3.64 (two m, 2H, Ts-O-CH 2 CH 2 -O); 3.76 (m, 1H, CH (CH 3 ) 2 ); 3.84 (m, 2H, O-CH- CH 2 -OTs); 4.08 (t, J=5.6Hz, 2H, Ts-O- CH 2 CH 2 -O); 7.3-7.8 (m, 8H, aromatic H's). 1,5-diiodo-2(R)-isopropyloxy-3-oxa-pentane ( C3 ) TLC on Kieselgel Plate F 254 (Merck), eluting system n-hexane/ethyl acetate (10/0.5 by volume) R f =0.40 1 HNMR (CDCl 3 , 200MHz) δ: 1.20, 1.22 (two d, J=6.4Hz, 6H, CH( CH 3 ) 2 ); 3.24 (d, J=5.6Hz, 2H, O-CH- CH 2 -J); 3.28 (t, J=6.7Hz, 2H, J- CH 2 CH 2 -O); 3.6-3.8 (m, 2H, J-CH 2 CH 2 -O); 3.94 (m, 1H, CH (CH 3 ) 2 ); 4.76 (t, J=5.6Hz, 1H, O- CH -CH 2 -J). Example 7 Preparation of 3'-deamino-3-[2(R)-isopropyloxyl-4-morpholinyl] doxorubicin ( A3 ) Doxorubicin hydrochloride (0.5 g) was reacted with compound C3 (3.2 g) following the same procedure reported in Example 3 to give the title compound A3 (0.21 g) as hydrochloride salt. TLC on Kieselgel Plate F 254 (Merck), eluting system methylene chloride/methanol (10/1 by volume) R f =0.55 FD-MS: m/e 708 (M+) 1 HNMR as free base (CDCl 3 , 200MHz) δ: 1.09, 1.16 (two d, J=6.0Hz, 6H, CH( CH 3 ) 2 ); 1.36 (d, J=6.6Hz, 3H, 5'- CH 3 ); 1.80 (m, 2H, 2'- CH 2 ); 2.15 (dd, J=4.0, 14.9Hz, 1H, 8ax- H ); 2.3-2.8 (m, 6H, CH 2 N CH 2 , 8eq- H , 3'- H ); 2.97 (d, J=18.8Hz, 1H; 10ax- H ); 3.26 (d, J=18.8Hz, 1H, 10eq- H ); 3.54 (m, 1H, O- CH (H)CH 2 N); 3.74 (s, 1H, 4'- H ); 3.81-4.1 (m, 3H, OCH( H )CH 2 N, 5'- H , O CH (CH 3 ) 2 ); 4.08 (s, 3H, O CH 3 ); 4.66 (s, 1H, 9- OH ); 4.68 (dd, J=2.2, 4.9Hz, 1H, O CH [OCH(CH 3 ) 2 ]CH 2 N); 4.75 (s, 2H, CO CH 2 OH); 5.28 (m, 1H, 7- H ); 5.55 (m, 1H, 1'- H ); 7.3-7.8 (m, 3H, aromatic H's); 13.24 (s, 1H, 11- OH ); 13.97 (s, 1H, 6- OH ). Example 8: 1,5-dihydroxy-2(S)-methoxy-3-oxa-pentane (E4) 1,5-dioxo-2(S)-methoxy-3-oxa-pentane (D4 ) (1.5 g, 11mmole), prepared as described in "Methods on Carbohydrate Chemistry" Acad.Press., Vol.1, 445, (1962), was dissolved in a mixture of water (10 ml) and methanol (10 ml) and treated with, sodiumborohydride (0,1g) dissolved in water (2 ml). After 20 minutes the solution was brought to pH 7 with an acidic resin Dowex 50WX2, filtered off and the solvent was removed under reduced pressure to give 1.4 g (Yield 93%) of the title compound, TLC on Kieselgel Plate F 254 (Merck), eluting system methylene chloride:methanol (10:1 by volume) brown spot at R f =0.24 after heating the TLC plate previously sprayed with sulforic acid. 1 HNMR (200 MHz, DMSO-d 6 ) δ: 3.26 (s, 3H, O CH 3 ); 3.4-3.6 (m, 6H, - CH 2 - CH 2 -O- CH - CH 2 -); 4.37 (t, J=5.4 Hz, 1H, O- CH -O); 4.40 (bm, 2H, HO -CH 2 CH 2 , CH 2 CH 2- OH ) Example 9 1,5-di(p-toluensulfonyl)oxy-2(S)-methoxy-3-oxa-pentane (F4 ) 1,5-dihydroxy-2(S)-methoxy-3-oxa-pentane (E4) (1.4 g, 10.3 mmole), prepared as described in Example 8, was dissolved in dry pyridine (10 ml) and treated at 0°C with p-toluensulfonylchloride (6.4 g, 0,034 mole). The mixture was kept at 4°C overnight, then was poured into an ice-water mixture and finally extracted with methylene chloride. The organic phase was washed with water, separated off, dried over anhydrous sodium sulphate, filtered off. The solvent was removed under reduced pressure. The crude material was chromatographed on a silicic acid column using methylene chloride as eluting agent to give 2.8 g (yield 62%) of pure title derivative. TLC on Kieselgel Plate F 254 (Merck), eluting system methylene chloride:acetone (95:5 by volume) brown spot at R f =0.55 after heating the TLC plate previously sprayed with sulforic acid. 1 HNMR (200 MHz, CDCl 3 ) δ: 2.44 (s, 6H, CH 3 -Ph); 3.27 (s, 3H, O CH 3 ); 3.69 (m, 2H, SO 2 OCH 2 CH 2 -O); 3.90 (m, 2H, SO 2 O CH 2 -CH-O); 4.11 (m, 2H, SO 2 O CH 2 CH 2 -O); 4.56 (t, J=5.3Hz, 1H,-O- CH -CH 2 ); 7.3-7.8 (m, 8H, aromatic H's). Example 10 Preparation of 1,5-diiodo-2(S)methoxy-3-oxa-pentane ( C4 ) 1,5-di(p-toluensulfonyl)oxy-2(S)-methoxy-3-oxa-pentane ( F4 ) (1.6 g, 3.6 mmole), prepared as described in Example 9, was dissolved in methylethylketone (30 ml) and treated with sodium iodide (3.04 g, 20.2 mmole) at 85°C for two days. After that, the solvent was removed in vacuo and the residue was added with n-hexane (50 ml) and water. The organic phase was separated off, dried over anhydrous sodium sulphate, filtered off. The solvent was removed under reduced pressure to give 1,5-diiodo-2(S)-methoxy-3-oxa-pentane ( C4 ) (1.2 g, yield 86%). TLC on Kieselgel Plate F 254 (Merck), eluting system methylene chloride, brown spot at R f =0.54 after heating the TLC plate previously sprayed with sulforic acid. 1 HNMR (200 MHz, CDCl 3 ) δ: 3.15 (m, 4H, J- CH 2 CH 2 -OCH- CH 2 -J); 3.40 (s, 3H, O CH 3 ); 3.80 (m, 2H, J-CH 2 CH 2 -O); 4.62 (t, J=5.6 Hz, 1H, O- CH -CH 2 ). Example 11 Preparation of 3'-deamino-[2"(S)-methoxy-4"-morpholinyl]-doxorubicin (A4) To a solution of doxorubicin hydrochloride (80 mg, 0.138 mmole) dissolved in dry dimethylformamide (4 ml) was added 1,5-diiodo-2(S)-methoxy-3-oxa-pentane ( C4 , 0.8 g, 2.06 mmole) and triethylamine (0.056 ml, 0.388 mmole). The reaction mixture was kept at room temperature under stirring for 36 hrs, then was poured in water and extracted with methylene chloride. After standard work up, the crude product was purified on silicic acid column using as eluting system amixture of methylene chloride methanol (97.5 : 2.5 by volume), to give, after treatment with methanolic anhydrous hydrogen chloride, 40 mg (yield 45%) of the title compound as hydrochloride salt. TLC on Kieselgel Plate F 254 (Merck), eluting system methylene chloride:methanol (19:1 by volume) R f =0.15 Free base: 1 HNMR (400 MHz, CDCl 3 ), δ: 13.98 (s, 1H, 6- OH ); 13.27 (s, 1H, 11- OH ); 8.03 (dd, J=1.1, 7.7Hz, 1H, 1- H ); 7.78 (dd, J=7.7, 8.6Hz, 1H, 2- H ); 7.39 (dd, J=1.1, 8.6Hz, 1H, 3- H ); 5.55 (m, 1H, 1'- H ); 5.30 (dd, J=2.1, 4.1Hz, 1H, 7- H ); 4.74 (d, J=4.5Hz, 14- CH 2 OH); 4.74 (S, 1H, 9- OH ); 4.49 [dd, J=2.6, 4.1Hz, 1H, NCH 2 - CH (OCH 3 )O]; 4.08 (s, 3H, 4-O CH 3 ); 3.94 (q, J=6.6Hz, 1H, 5'- H ); 3.93 [m, 1H, NCH 2 CH (H)O]; 3.67 (m, 1H, 4'- H ); 3.54 [m, 1H, NCH 2 CH (H)O]; 3.38 [s, 3H, NCH 2 CH-O CH 3 ]; 3.27 (dd, J=19, 18.8Hz, 1H, 10- H eq); 3.04 (d, J=18.8Hz, 1H, 10- H ax); 3.00 (t, J=4.5Hz, 1H, CH 2 OH ); 2.60 [dd, J=4.l, 11.4Hz, 1H, N CH (H)CHOCH 3 ]; 2.6-2.5 (m, 3H, N CH (H)CHOCH 3 , N CH 2 CH 2 O); 2.4-2:3 (m, 2H, 8- H eq, 3'- H ); 2.15 (dd, J=4.1, 14.7Hz, 8- H ax); 1.76 (m, 2H, 2'- CH 2 ); 1.26 (d, J=6.6Hz, 3H, 5'- CH 3 ). Example 12 Preparation of 1,5-dihydroxy-2(R)-methoxy-3-oxa-pentane (E5) The title compound was prepared as described in Example 8 starting from 1,5-dioxo-2(R)-methoxy-3-oxa-pentane (D5 ) which in turn can be prepared as described in "Methods on Carbohydrate Chemistry" Acad.Press., Vol.1, 445, (1962). TLC on Kieselgel Plate F 254 (Merck), eluting system methylene chloride:methanol, brown spot at R f =0.24 after heating the TLC plate previously sprayed with sulforic acid. Example 13 Preparation of 1,5-di(p-toluensulfonyl)oxy-2(R)-methoxy-3-oxa-pentane (F5 ) 1,5-dihydroxy-2(R)-methoxy-3-oxa-pentane (E5), prepared as described in Example 12, was transformed into the title compound F5 following the same procedure reported in Example 9. TLC on Kieselgel Plate F 254 (Merck), eluting system methylene chloride: acetone (95:5 by volume) brown spot at R f =0.55 after heating the TLC plate previously sprayed with sulforic acid. Example 14 Preparation of 1,5-diiodo-2(R)-methoxy-3-oxa-pentane ( C5 ) 1,5-di(p-toluensulfonyl)oxy-2(R)-methoxy-3-oxa-pentane ( F5 ), prepared as described in Example 13, was converted into the diiodo derivative C5 following the procedure described in Example 10, TLC on Kieselgel Plate F 254 (merck), eluting methylene chloride, system brown spot at R f =0.54 after heating the TLC plate previously sprayed with sulfuric acid. Example 15 Preparation of 3'-deamino-[2"(R)-methoxy-4"-morpholinyl]-doxorubicin (A5) The title compound was prepared by condensing doxorubicin hydrochloride with 1,5-diiodo-2(R)-methoxy-3-oxa-pentane (C5), prepared as above described, following the procedure reported in Example 11. TLC on Kieselgel Plate F 254 (Merck), eluting system methylene chloride:methanol (19:1 by volume) R f =0.13 Free base: 1 HNMR (400 MHz, CDCl 3 ) δ: 13.97.(s, 1H, 6- OH );.13.25 (s, 1H, 11- OH ); 8.03)(dd,J=1,1, 7.7Hz, 1H, 1- H ); 7.78 (dd, J=7.6, 7.7Hz; 1H, 2- H ); 7.39 (dd, J=1.1, 7.6Hz,1H, 3- H ); 5.53 (d, J=3.4Hz, 1H, 1'- H ); 5.29 (dd, J=2.5,- 4.1Hz, 1H, 7- H ); 4.75 (s, 2H, 14- CH 2 OH); 4.71 (s, 1H, 9- OH ); 4.46 [dd, J=2.6, 4.7Hz, 1H, NCH 2 - CH (OCH 3 )O]; 4.08 (s, 3H, 4-O CH 3 ); 3.93 (q, J=6.6Hz, 1H, 5'- H ); 3.92 [m, 1H, NCH 2 CH (H)O]; 3.70 (m, 1H, .4'- H ); 3.56 [m, 1H, NCH 2 CH (H)O]; 3.40 [s, 3H, NCH 2 CH-O CH 3 ]; 3.26 (dd, J=19, 19.9Hz, 1H, 10- H eq); 3.03 (d, J=19.9Hz, 1H, 10- H ax); 2.66 [dd, J=2.6, 11.4Hz, 1H, N CH (H)CHOCH 3 ]; 2.53 (m, 1H, N CH (H)CH 2 O); 2.5-2.3 (m, 4H, N CH (H)CH 2 O, N CH (H)CHOCH 3 , 8- H eq, 3'- H ); 2.15 (dd, J=4.1, 14.7Hz, 8- H ax); 1.8-1.7 (m, 2H, 2'- CH 2 ); 1.36 (d, J=6.6Hz, 3H, 5'- CH 3 ).

Claims: A diiodo compound of formula C: wherein X is a methyl or benzyl group. A process for the preparation of a diiodo compound of formula C as defined in claim 1, which process comprises: (a) subjecting to periodate oxidation a compound of formula S·· : wherein X is as defined in claim 1; (b) reducing the thus-obtained dialdehyde derivative of formula D·: wherein X is as defined above; (c) sulfonating the thus-obtained dihydroxy derivative of formula E·: wherein X is as defined above; and (d) iodinating the sulfonated derivative thus obtained. A process according to claim 2, wherein D- or L-arabinose is reacted with an alcohol X-OH, wherein X is as defined in claim 1, thereby to form the compound of formula S··. A process according to claim 2, wherein the dihydroxy derivative of formula E· is reacted with p-toluenesulfonyl chloride in step (c).

Inventors: BARGIOTTI ALBERTO, FAIARDI DANIELA, GRANDI MARIA, SUARATO ANTONINO, BARGIOTTI, ALBERTO, FAIARDI, DANIELA, GRANDI, MARIA, SUARATO, ANTONINO
Applicants: PHARMACIA SPA, PHARMACIA S.P.A.
Application year: 1990
Main classification: C07H15
IPC codes: C07C43, A61K31, A61P35, C07H15, C07H19