Benzo[b] thiophene derivatives. XIV. Derivatives of naphtho[1,8-c] thiophene

In the course of our efforts to synthesize the sulfur isostere of lysergic acid, we have prepared a number of derivatives of the little known naphtho1,8-bc]thiophene ring system. Two previously reported compounds, 2-bromo-3,4-dihydro-5-oxo-5H-naphtho1,8-bc]thiophene and 2-bromo-5-hydroxy-3,4-dihydro-5H-naphtho1,8-bc] thiophene have been obtained pure for the first time, and the syntheses and spectral data of eighteen new compounds are presented. The new compounds include alcohols, ketones, and halogen derivatives of partially reduced naphtho-1,8-bc] thiophene, as well as the sulfones of several of these compounds.