Benzoic acid, 2-[(1-ethyl-2-methyl-1H-indol-3-yl)carbonyl]- → Phthalide

Participants

Reaction Steps

A mixture of 7.7 g of 3-(2'-carboxybenzoyl)-1-ethyl-2-methylindole and 7.9 g of bis(n-butylamino)phenol n-butyl ether in 30 g of acetic anhydride is stirred for 1 hour at 80°-85° C. Working up as described in Example 1 gives 14 g of a phthalide of formula ##STR11## This amorphous compound has a softening point of 40° C. and develops at once a lightfast blue image on acid-modified clay.

Provenance & Evidence