The Synthesis of N-Substituted Ureas I: The N-Alkylation of Ureas

Article abstract of DOI:10.1007/BF00816855

Urea and N-alkylureas are N'-alkylated in low yields using aprotic dipolar solvents, like dimethylsulfoxide, solid potassium hydroxide, and alkyl halides.Phase transfer catalysis with tetrabutylammonium chloride in refluxing toluene results in high yield