Carbonohydrazide and its thio-analogue undergo di-addition with ethoxycarbonyl isothiocyanate. The reaction terminates at the mono-addition stage when one of the hydrazine moieties of the (thio)carbonohydrazide is blocked. The resulting 6-(substiiuted)amino-1-ethoxycarbonyl-thiobiureas and bithioureas are cyclised to the appropriate 1-ethoxycarbonamido-1,3,4-thiadiazoles by acids, and to mercapto-1
碳酰
肼及其
硫代类似物与乙氧基羰基异
硫氰酸酯进行双加成反应。当(
硫代)碳酰
肼的
肼部分之一被封端时,反应在单加成阶段终止。将所得的6-(取代的)
氨基-1-乙氧基羰基-
硫代双
脲和联
硫脲通过酸环化为合适的1-乙氧基碳酰胺基-1,3,4-
噻二唑,并通过碱环化为巯基-
1,2,4-三唑。