De, Asish; Brunskill, John S. A.; Jeffrey, Howard, Indian Journal of Chemistry - Section B Organic and Medicinal Chemistry, 1984, vol. 23, # 10, p. 918 - 925
The present invention relates to novel direct dyes and compositions comprising them for dyeing keratin fibers especially human hair. The novel dyes of the present invention have benzothiophene structure providing intensive and homogeneous dyeing on keratin fibers, especially human hair.