This article by Dr. Vikas N. Telvekar and Dr. Ajit G. Nagarkar is published in Letters in Organic Chemistry, Volume 15, Issue 15, 2018
Researchers from the Institute of Chemical Technology, Mumbai have reported a simple and efficient method for the synthesis of different unsymmetrical N,N'-disubstituted urea and N-substituted urea derivatives using L-proline as an environmental friendly (in other words, green) catalyst. L-proline is a naturally occurring molecule which can be used to synthesize substituted urea products in a one pot reaction. The researchers mixed aniline derivatives with urea in a mixture of toluene and L-proline and heated this at 100 Celsius for several hours. The methodology is applicable for synthesizing various derivatives of phenylurea, diphenyl urea (which have applications in pharmaceutical research) with excellent yield at mild conditions.