A greener procedure for the synthesis of α-ureidophosphonates under ultrasound irradiation. An X-ray crystallographic study†
Abstract
An efficient, eco-sustainable and greener procedure for the synthesis of α-ureidophosphonates via a one-pot three-component reaction of aldehydes, urea/thiourea and triethylphosphite or diethylphosphite using ultrasonic irradiation under solvent- and catalyst-free conditions at 75°, is developed. The desired products were obtained in excellent yields within short reaction times (15–30 min). Crystals of diethyl[α-ureido-(4-methylphenyl)]methyl phosphonate suitable for X-ray study have been obtained after recrystallization in a mixture of diethyl ether and n-hexane. The detailed analysis of the molecular and crystal structure is presented.