4-甲基-5-甲酰基噻唑的合成

Synthesis of 4-Methyl-5-formylthiazole

以氯丙酮和硫脲为起始原料,经环合、Vilsmeier甲酰化、重氮化还原得到头孢托仑匹酯关键中间体4-甲基-5-甲酰基噻唑,反应总收率为42.8%。重点考察了Vilsmeier甲酰化反应中双(三氯甲基)碳酸酯(BTC)/DMF用量、反应温度和反应时间对中间体4收率的影响,得出了较佳的工艺条件,并对其反应机理进行了探讨。

Starting from the 1-chloropropan-2-one and thiourea, the key intermediate of cefditoren pivoxil was achieved through cyclization, Vilsmeier formylation and diazotization reduction in an overall yield of 42.8%. The effects of the amount of bis（trichloromethyl）carbonate （BTC）/DMF, temperature and reaction time on the yield of the intermediate 4 were screened to afford the optimized conditions. A plausible mechanism for the formation of 1 from 3 was given.