Microwave Assisted Synthesis of 4-Substituted 1-Ethoxycarbonyl Semicarbazides from Ethyl Carbazate and Isocyanates
作者:Shadpour Mallakpour、Abdol Reza Hajipour、Hedayat A. Taghizadeh
DOI:10.1007/s00706-003-0012-6
日期:2003.6
A rapid and simple method for the preparation of 4-substituted 1-ethoxycarbonyl semicarbazide is reported. The reaction is carried out under microwave irradiation by the reaction of five different isocyanates with ethyl carbazate.
Alternative synthetic routes to N-methyl-1,2,4-triazoline-3,5-dione (MeTAD) and other triazolinedione derivatives
作者:Gary W. Breton、Mark Turlington
DOI:10.1016/j.tetlet.2014.06.091
日期:2014.8
N-Methyl-1,2,4-triazoline-3,5-dione (MeTAD) is a powerful electrophile and a versatile synthetic reagent. In this Letter we describe two methods for the synthesis of N-methylurazole, the direct precursor to MeTAD, on gram scales and in good yields. Both methods provide pure urazole while avoiding the necessity of large scale purification via column chromatography or recrystallization. One of the methods proved to be amenable for the synthesis of derivatives other than N-methyl. (C) 2014 Elsevier Ltd. All rights reserved.