Efficient and Regioselective Synthesis of 2-Alkyl-2 H-indazoles

M Cheung, A Boloor, JA Stafford

Index: Cheung, Mui; Boloor, Amogh; Stafford, Jeffrey A. Journal of Organic Chemistry, 2003 , vol. 68, # 10 p. 4093 - 4095

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Citation Number: 38

Abstract

Auwers et al. reported a regioselective methylation at the 2-position of 6-nitro-1H-indazole by heating with methyl iodide (4 equiv) at 100 °C in a sealed tube for 4 h; 2 however, no yield was mentioned in the report. When we repeated this experiment, 2-methyl-6-nitro-2H-indazole was isolated in about 30% yield with a trace of 1-methylated product. Upon heating the reaction for 15 h, only dimethylated product (1,2-dimethyl-6-nitroindazolium iodide) was observed. ...