Studies on heterocyclic enaminonitriles. IV. Reaction of ethyl N-(3-cyano-4,5-dihydro-2-thienyl)oxamates with cyanomethylene compounds in the presence of triethylamine.
作者:SHIZUKO HACHIYAMA、KAZUKO KOYANAGI、YUKIHIKO TOMIOKA、MOTOYOSHI YAMAZAKI
DOI:10.1248/cpb.31.1177
日期:——
Ethyl N-(3-cyano-4, 5-dihydro-2-thienyl) oxamate (Ia) reacted with ethyl or methyl cyanoacetate, α-cyanoacetamide and 1-cyanoacetylpyrrolidine in the presence of triethylamine to form the corresponding 2-[4-amino-5, 6-dihydrothieno [2, 3-d] pyrimidine] acetic acid derivatives (IIa-1-IIa-4). Similarly, ethyl N-[3-cyano-5-methyl (or 4-phenyl)-4, 5-dihydro-2-thienyl] oxamate (Ib or Ic) gave the corresponding 2-[4-amino-5, 6-dihydrothieno-[2, 3-d] pyrimidine] acetic acid derivatives (IIb-1-IIb-4 or IIc-1-IIc-4). On acidic hydrolysis, IIa-1, 2, IIb-1, 2 and IIc-1, 2 were converted to 4-amino-2-methyl-5, 6-dihydrothieno [2, 3-d] pyrimidines (IIIa-c).
N-(3-氰基-4, 5-二氢-2-噻吩基)草氨酸乙酯(Ia)与氰乙酸乙酯或氰乙酸甲酯、α-氰乙酰胺和 1-氰乙酰基吡咯烷在三乙胺存在下反应,生成相应的 2-[4-氨基-5, 6-二氢噻吩并[2, 3-d]嘧啶]乙酸衍生物(IIa-1-IIa-4)。同样,N-[3-氰基-5-甲基(或 4-苯基)-4, 5-二氢-2-噻吩基]草氨酸乙酯(Ib 或 Ic)可以得到相应的 2-[4-氨基-5, 6-二氢噻吩并[2, 3-d]嘧啶]乙酸衍生物(IIb-1-IIb-4 或 IIc-1-IIc-4)。酸性水解时,IIa-1,2、IIb-1,2 和 IIc-1, 2 转化为 4-氨基-2-甲基-5,6-二氢噻吩并[2,3-d]嘧啶(IIIa-c)。