4-Toluenesulfonyl chloride → methyl 1-tosyl-1H-indole-4-carboxylate

Participants

Reaction Steps

A solution of 21 g of indole-4-carboxylic-acid-methylester in 100 ml of methylene-chloride, 24.9 ml of triethylamine and 7.34 g of 4-dimethyl-aminopyridine is proportionately mixed at 0° C. with 34.2 g of p-toluene-sulfonic-acid-chloride. After 16 h at 0° C., the mixture is diluted with methylene chloride, washed neutral with saturated sodium bicarbonate solution and NaCl solution, and the solvent is distilled off in vacuum. 35.37 g of 1-tosylindole-4-carboxylic-acid-methylester with a m.p. of 145°-147° C. (diisopropylether) is obtained.

Provenance & Evidence