【摘要】 以廉价的2-氨基-噻唑-4-甲酸甲酯为原料,经Na NO2重氮化后脱去氨基,次磷酸还原制得噻唑-4-甲酸甲酯,再用KBH4/Li Cl还原,次氯酸钠氧化制得噻唑-4-甲醛,总收率达34. 79%,产物经质谱、红外、核磁表征。考察了反应温度、还原体系和硼氢化钾用量对产物收率的影响,最佳还原条件为n(噻唑-4-甲酸甲酯)∶n(KBH4/Li Cl)=1∶1. 5,反应温度为80℃,还原反应收率达75. 3%。更多还原

【Abstract】 Thiazole-4-carboxaldehyde was synthesized from cheap methyl 2-aminothioazole-4-carboxylate via two steps. The first step was diazotization-reduction of compound 2 by using sodium nitrite and phosphonous acid. The second step was the reduction of ester 3 by potassium borohydride/lithium chloride system,followed by oxidation using sodium chlorite in the presence of TEMPO under mild condition. The total yield was 34. 79%,and the structure was characterized by1 H-NMR,IR and MS. The effects of reaction temperature,reductants and dosage of KBH4 on the yield of the product were investigated. The mole ratio of methyl-thiazole-4-carboxylate to KBH4/Li Cl was 1 ∶ 1. 5,and the reduction temperature was 80 ℃. The yield of reduction reaction was 75. 3%.更多还原