Synthesis of Peptidyl Ureas Using p‐Nitrophenyl‐(9‐fluorenylmethoxy Carbonylamino)methyl Carbamate Derivatives

Abstract

An efficient synthesis of p‐nitrophenyl‐(9‐fluorenylmethoxy carbonylamino) methyl carbamates using isocyanates derived from Fmoc‐amino acid azides and p‐nitrophenol in presence of an equimolar quantity of N‐ethyldiisopropyl amine is described. All the carbamates have been isolated as crystalline solids and are fully characterized. Further, their utility for the synthesis of dipeptidyl ureas has been demonstrated.

Keywords:

• Peptidyl ureas
• N‐Ethyldiisopropyl amine
• Equimolar quantity
• Isocyanate derivative

Acknowledgments

We are grateful to Department of Science and Technology, Govt. of India for financial assistance. We thank Sophisticated Instruments Facility, I. I. Sc., for NMR data and Hikal India Ltd., Bangalore for optical rotation measurements.