Heterocyclization of 1-aryl/alkyl-2-thiobiureas to 4-aryl/alkyl-3-substituted-Δ 2 -1,2,4-triazolin-5-ones
摘要:
Synthesis of a range of 1,2,4-triazolin-5-ones has been carried out by thermally induced cyclization of 1-aryl/alkyl-2-alkyl isothiobiureas 4. The required isothiobiureas were generated in situ by the reaction of alkyl halides with 1-aryl/alkyl-2-thiobiureas 3 in acidic medium at reflux. The reaction proceeds after S-alkylation of the thiobiureas and is demonstrated by the isolation of the alkyl isothiobiurea intermediates and their subsequent acid catalyzed thermal cyclization. (C) 2001 Elsevier Science Ltd. All rights reserved.
Heterocyclization of 1-aryl/alkyl-2-thiobiureas to 4-aryl/alkyl-3-substituted-Δ 2 -1,2,4-triazolin-5-ones
作者:M.M Suni、Vipin A Nair、C.P Joshua
DOI:10.1016/s0040-4020(01)00018-7
日期:2001.3
Synthesis of a range of 1,2,4-triazolin-5-ones has been carried out by thermally induced cyclization of 1-aryl/alkyl-2-alkyl isothiobiureas 4. The required isothiobiureas were generated in situ by the reaction of alkyl halides with 1-aryl/alkyl-2-thiobiureas 3 in acidic medium at reflux. The reaction proceeds after S-alkylation of the thiobiureas and is demonstrated by the isolation of the alkyl isothiobiurea intermediates and their subsequent acid catalyzed thermal cyclization. (C) 2001 Elsevier Science Ltd. All rights reserved.
Heterocyclization of 1-alkyl-2-thiobiureas with α-haloketones
作者:M.M. Suni、Vipin A. Nair、C.P. Joshua
DOI:10.1016/s0040-4039(00)01893-1
日期:2001.1
1-Alkyl-2-thiobiureas on reaction with α-haloketones such as p-methoxyphenacyl bromide, p-methylphenacyl bromide, p-chlorophenacyl bromide and phenacyl bromide, were found to afford semicarbazonothiazolines in good yields.