Y. Tominaga, R. Pratap, R. Castle
Jul 1, 1982
Citations
0
Influential Citations
26
Citations
Journal
Journal of Heterocyclic Chemistry
Abstract
All isomers of the monomethylbenzo[b]naphth[2,1-d]thiophenes were synthesized using photocyclization of 3-styrylbenzo[b]thiophenes. The 1-, 3-, 4-, and 5-methylbenzo[b]naphtho[2,1-d]thiophenes were synthesized by irradiation of the corresponding methylated 3-styrylbenzo[b]thiophenes which were prepared by the Wadsworth-Emmons reaction of diethyl benzo[b]thenylphosphonate with o-, m-, p-tolualdehyde and acetophenone. The 7-, 8-, 9- and 10-methylbenzo[b]naphtho[2,1-d]thiophenes were synthesized by decarboxylation of 7-, 8-, 9- and 10-methylbenzo[b]naphtho[2,1-d]thiophene-6-carboxylic acid with copper in quinoline. These carboxylic acids were prepared by photocyclization of the corresponding 2-(benzo[b]thiophen-3-yl)-3-phenylpropenoic acids which were prepared by the condensation of the methylated benzo[b]thiophene-3-ylacetic acids with benzaldehyde in the presence of triethylamine in acetic anhydride.