Acylation of 2-methyl-2-thiazoline

The acylation of 2-methyl-2-thiazoline initially reported by Sheehan etal. (1) has been reinvestigated and reinterpreted. The initially formed 2-chloro-N-acylthiazolidine (e.g. 8) can be dehydrohalogenated to a 2-methylene-N-acylthiazolidine by reaction with triethylamine or converted to a 2-hydroxy-N-acylthiazolidine on addition of water. Contrary to the earlier report no 2-methyl-N-acyl-4-thiazolines are produced when the reaction is carried out in benzene at 60° and in the presence of excess triethylamine.