2‐Trifluoroacetyl‐1‐methoxycycloalkenes: A convenient precursor for the synthesis of geminated polymethylene trifluoromethyl substituted heterocycles

Abstract

Abstract magnified image This article describes the methodology that allows the simultaneous introduction of a trifluoromethyl group and a 7‐, 8‐, and 10‐membered cycloalkane ring fused to heterocyclic derivatives. A series of 10 geminated polymethylene trifluoromethyl substituted isoxazolines, pyrazoles, pyrimidinones, and a pyrazolyl‐quinoline were obtained in moderate to good yields from the reaction of three 2‐trifluoroacetyl‐1‐methoxycycloalkenes derived from cycloheptanone, cyclooctanone, and cyclododecanone with hydroxylamine hydrochloride, hydrazine hydrochloride, urea, and 7‐chloro‐4‐hydrazinoquinoline. J. Heterocyclic Chem., (2009).