Study on the Alkylation and Sulfonylation of 3-Aryl-1-methyl-1,2,4-triazolin-5-ones

Abstract
The alkylation and sulfonylation of 3-aryl-1-methyl-1,2,4-triazolin-5-ones (1) were studied with various alkyl halides and sulfonyl chlorides. The alkylation of 1 with methyl iodide and ethyl bromide afforded N-alkylated products, however with methyl 2-bromopropionate afforded O-alkylated products predominantly. The sulfonylation by methanesulfonyl chloride afforded a mixture of N-sulfonylated and O-sulfonylated products, while the sulfonylation by p-toluenesulfonyl chloride afforded mainly O-sulfonylated products.