Alkoxy Isothiocyanates as Intermediates in the Flash Vacuum Pyrolysis of Alkoxythioureas
作者:Carl Th. Pedersen、Frank Jensen、Robert Flammang
DOI:10.1071/ch08406
日期:——
isolation IR spectroscopy following flash vacuum pyrolysis (FVP) of N-methoxythioureas, N-tert-butyl-N′-methoxythiourea 1d being the best precursor. Isothiocyanates 3, amines, and aldehydes are also generated by FVP of several substituted N-alkoxythioureas 1 in the temperature range 400–800°C. The formation of these products can be explained either by secondary pyrolysis of initially formed alkoxy isothiocyanates
异硫氰酸甲氧基的MeO-NCS 2B是由基质隔离IR光谱以下的闪光真空热解(FVP)检测Ñ -methoxythioureas,ñ -叔丁基- ñ '-methoxythiourea 1D是最好的前体。在400-800°C的温度范围内,几种取代的N-烷氧基硫脲1的FVP也会生成异硫氰酸酯3,胺和醛。这些产物的形成可以通过初始形成的烷氧基异硫氰酸酯2的二次热解,或通过自由基机理对1中的O–N键进行初始裂解来解释。N-氰胺4和/或互变异构碳二亚胺5是通过另一途径形成的。通过IR光谱和在线质谱或串联质谱监测热解,并且反应机理得到理论计算的支持。