Monatshefte f€ ur Chemie 134, 1015–1017 (2003) DOI 10.1007/s00706-003-0012-6 Microwave Assisted Synthesis of 4-Substituted 1-Ethoxycarbonyl Semicarbazides from Ethyl Carbazate and Isocyanates Shadpour Mallakpour ; a , Abdol Reza Hajipour, and Hedayat A. Taghizadeh Organic Polymer Chemistry Research Laboratory, College of Chemistry, Isfahan University of Technology, Isfahan 84156, Iran Received October 28, 2002; accepted October 31, 2002 Published online May 15, 2003 # Springer-Verlag 2003 Summary. A rapid and simple method for the preparation of 4-substituted 1-ethoxycarbonyl semi- carbazide is reported. The reaction is carried out under microwave irradiation by the reaction of five different isocyanates with ethyl carbazate. Keywords. Microwave irradiation; Solid-state; Semicarbazide. Introduction 4-Substituted 1-ethoxycarbonyl semicarbazides are important organic intermediates for the synthesis of 4-substituted urazoles and they are prepared by reaction of the corresponding isocyanates with ethyl carbazate in toluene solution [1]. However, some of the mentioned methods invariably require lower temperatures, long reaction times, and involve solvents which are toxic and detrimental to the environment. Therefore, there is a need for a simple, less expensive, and safer method for synthesis of semicarbazides. In recent years, there has been a growing interest in the applica- tion of microwave irradiation in chemical reaction enhancement, because of cleaner reactions, decreased reaction times, and easier work-up [2]. In continuation of our program [3] we now report a facile preparation of semicarbazides from ethyl carba- zate and isocyanates accelerated under microwave irradiation. Results and Discussion One equivalent of ethyl carbazate and phenyl isocyanate were ground in a mortar until a homogeneous mixture is formed (1 min). Then, the reaction mixture was transferred  Corresponding author. E-mail: mallak@cc.iut.ac.ir a Previous name. Shadpour E. Mallakpour