申请人:Degussa Aktiengesellschaft
公开号:US04661626A1
公开(公告)日:1987-04-28
There are produced 2-isocyanato-2,3-dehydrocarboxylic acid esters of the general formula: ##STR1## in which R.sup.1 is a straight chain or branched C.sub.1 -C.sub.4 -alkyl group, a phenyl group or a benzyl group, R.sup.2 is hydrogen or a methyl group and R.sup.3 is hydrogen, a straight chain or branched C.sub.1 -C.sub.16 -alkyl group, a C.sub.3 -C.sub.8 -cycloalkyl group, a C.sub.1 -C.sub.6 -alkylmercapto group or a phenyl group by reacting a 2-azido-carboxylic acid ester of the general formula: ##STR2## in an inert solvent at a temperature between 0.degree. and 150.degree. C. with phosgene or diphosgene in the presence of a perrhenate. The compounds of general formula (I) can be converted into the corresponding Z- or BOC-protected 2,3-dehydro-2-amino-carboxylic acid ester with benzyl alcohol or with tert. butyl alcohol, which esters in turn are valuable building blocks for the synthesis of dehydropeptides.
通式为:##STR1## 的2-异氰酸基-2,3-脱羧酸酯可通过以下反应制得:将通式为:##STR2## 的2-叠氮基羧酸酯与氯甲酰或二氯甲酰在惰性溶剂中在0℃至150℃的温度下,在过钨酸钾的存在下反应,其中R1为直链或支链C1-C4烷基,苯基或苄基,R2为氢或甲基,R3为氢,直链或支链C1-C16烷基,C3-C8环烷基,C1-C6烷基硫基或苯基。通式(I)的化合物可以通过与苄醇或叔丁基醇反应,转化为相应的Z-或BOC-保护的2,3-脱氢-2-氨基-羧酸酯,这些酯又是合成脱氢肽的有价值的构建块。