4-Nitro-及び5-Nitro-N-(2-nitroxyethyl) nicotinamideの合成
1986 年 106 巻 10 号 p. 872-877
詳細
1986 年 106 巻 10 号 p. 872-877
The following results were obtained during synthetic studies of 4-and 5-nitro derivatives (7 and 8) of N-(2-nitroxyethyl) nicotinamide, a new antianginal drug (I).
1) Nicotinic acid 1-oxide (1a) and its derivatives (1b, c, d) resisted γ-nitration, whereas the methyl ester (1b) underwent β-nitration on treatment with N-nitropyridinium tetrafluoroborate at room temperature in dichloromethane. 2) 4-Nitronicotinic acid 1-oxide (2a) was successfully converted to the methyl ester (2b) and the amide (2c) in good yields by treatment with diazomethane and through the active ester with 1-hydroxybenzotriazole, respectively. 3) Deoxygenation of 2b and 2c was smoothly effbcted with phosphoryl bromide, but that of 2a gave no 4-nitronicotinic acid. 4) On the basis of these findings, 7 and 8 were synthesized starting from 2a through the amide 2f, and from 5-nitronicotinic acid, respectively.
