2,5-dihydrothiazoles are prepared by reacting aza-alkylene-dienes with sulfur at relatively low temperatures for example below about 160.degree. C. Where the reaction is carried out at relatively higher temperature, for example above about 160.degree. C., such as 160.degree. to 250.degree. C., 4,5-dihydrothiazoles are formed. In addition 2,5-dihydrothiazoles can be converted to 4,5-dihydrothiazoles by heating them to temperatures above about 160.degree. C.
2,5-二氢
噻唑可以通过在相对较低的温度下(例如低于约160℃)将氮杂-烯
丙烯与
硫反应制备而成。如果在相对较高的温度下进行反应,例如在160℃至250℃之间,会形成4,5-二氢
噻唑。此外,将2,5-二氢
噻唑加热至约160℃以上的温度可以将其转化为4,5-二氢
噻唑。