An efficient transformation of ethers to N,N′-disubstituted ureas in a Ritter type reaction

A simple, mild, and an alternative protocol for the preparation of N,N′-disubstituted ureas from readily available ethers and cyanamides as starting materials is described. The protocol explores the reactivity of ether in a Ritter type reaction with cyanamide in the presence of BF3·Et2O and resulting in the formation of N,N′-disubstituted urea. Divinyl ether as well as MTBE (methyl tert-butyl ether) can be employed as ether components to afford allyl and tert-butyl ureas respectively.