| 摘要 |
PROBLEM TO BE SOLVED: To readily produce a high-purity 2-alkylindoline useful as a synthetic intermediate raw material for medicines, agrochemicals, photosensitive materials, dyes, etc., in high yield by catalytically reducing an alkylindole in the presence of a specific acid with hydrogen. SOLUTION: A 2-alkylindole of formula I (R is a 1-4C alkyl) is reduced with hydrogen in the presence of a platinum carbon catalyst and an acid to afford a 2-alkylindoline of formula II. Furthermore, the platinum carbon catalyst is used in an amount of 0.05-1wt.% based on the 2-alkylindole of formula I and sulfuric acid is used in an amount of >=1 equiv. based on the compound of formula I. 2-Methylindole can be used as the compound of formula to provide 2-methylindoline. |
