反应详情

Cold methylhydrazine (1.6 ml, 30 mmol) was added to a stirred solution of 5'-O-(t-butyldimethylsilyl)-3'-O-phthalimidothymidine (2, 4.6 g, 9.18 mmol) in dry CH2Cl2 (60 ml) at 5°-10° C. After 10 minutes white precipitation of 1,2-dihydro-4-hydroxy-2-methyl-1-oxophthalizine occurred. The suspension was stirred at room temperature for 1 h. The suspension was filtered and precipitate washed with CH2Cl2 (2×20 ml). The combined filtrates were concentrated and the residue purified by silica gel column chromatography. Elution with CH2Cl2 :MeOH (100:0→97:3, v/v) furnished the title compound (3.40 g, 100%) as white solid. Crystallization from CH2Cl2 gave white needles, m.p. 171° C.; 1H NMR (CDCl3) δ0.05 [s, 6, (CH3)2 ], 0.90 [s, 9, (CH3)3 ], 2.22-2.58 (2m, 2, 2'CH2), 3.9-4.08 (m, 3, 5'CH2, and 3'H) 4.30 (m, 1, 4H) 5.5 (br s, 2, NH2) 6.2 (m, 1, 1'H) 7.45 (s, 1, C6H) 8.9 (br s, 1, NH).

1. customAfter 10 minutes white precipitation of 1,2-dihydro-4-hydroxy-2-methyl-1-oxophthalizine
2. filtrationThe suspension was filtered
3. washprecipitate washed with CH2Cl2 (2×20 ml)
4. concentrationThe combined filtrates were concentrated
5. customthe residue purified by silica gel column chromatography
6. washElution with CH2Cl2 :MeOH (100:0→97:3