SYNTHESIS OF 8,9-DIHYDROPYRIMIDO[4,5-e][1,4]OXAZEPIN-7(5H)-ONES BY THE REACTION OF 1-(4-CHLOROPYRIMIDIN-5-YL)ALKAN-1-OLS WITH N-ALKYLGLYCINES

摘要

A facile method for the construction of a new ring system, 8,9-dihydropyrimido[4,5-e][1,4]oxazepin-7(5H)-one, is described. The key feature of the synthetic route includes substitution of one of the two chloro groups of 1-(4,6-dichloropyrimidin-5-yl)alkan-1-o1 derivatives, which can easily be derived from the reaction between 5-lithiated compound of 4,6-dichloro-2-(methylsulfanyl)pyrimidine (DCSMP) and aldehydes, with N-alkylglycines in the presence of triethylamine, followed by lactonization of the resulting hydroxy acids catalyzed by in situ generated triethylamine hydrochloride.