5H-Indeno[1,2-d]pyrimidin-5-ones

Abstract

2-(1?-Ethoxyethylidene)indandione (4) and formamidine react to give 4- methyl-5H-indeno[1,2-d]pyrimidin-5-one (5a). Similarly 2-methyl-(5b), 2-trichloro-methyl- (5c), 2-trifluoromethyl- (5d), 2-amino- (5e), and 2-methylthio-4-methyl-5H-indeno[1,2-d]pyrimidin-5-one (5f) have been prepared using the respective amidines, guanidine, or methylisothiourea. Urea and thiourea failed to react and gave instead molecular addition compounds.     2-Hydroxymethyleneindan-1-one (6) with urea or thiourea reacts to give the 2-(ureidomethylene)-(7a) or 2-(thioureidomethylene)-indan-1- one (7b). All attempts to cyclize these compounds to give pyrimidines failed.     The alkaline hydrolysis and bromination of the indenopyrimidines have been investigated.