Reactions of heterocycles with thiophosgene. Part IV. β,4-Dichloro-2-isothiocyanatocinnamaldehyde, a product from 4,7-Dichloroquinoline
Abstract
4,7-Dichloroquinoline undergoes ring scission on reaction with thiophosgene and barium carbonate. The resulting β-chloroisothiocyanatocinnamaldehyde [(6) or (7)] reacts with a wide variety of nucleophiles to give 2-substituted 4-formylmethylene-4H-3,1-benzothiazines. Some reactions of the 2-morpholinobenzothiazine (13) are described.