Formation of pentaatomic lactones on the 2,3-positions of benzo[b]furan, benzo[b]thiophene, and benzo[b]selenophene was written by Christiaens, L.;Renson, M.. And the article was included in Bulletin des Societes Chimiques Belges in 1972.Quality Control of 3-Bromo-2-methylbenzo[b]thiophene This article mentions the following:
Attempted lactonization of the isomeric hydroxymethyl carboxylic acids I and II (X = O, S, Se) with Ac2O gave only III (X = Se) and IV (X = S, Se). I (X = O, S) and III (X = O) would not cyclize but were acetylated to various degrees. III (X = S) was obtained by cyclizing 2-cyano-3-(hydroxymethyl)benzothiophene. I were prepared by brominating the 3-methyl analogs, subjecting the bromomethyl compounds to Sommelet reaction and NaBH4 reduction II (X = O) was also prepared from the 2-methyl analog, and II (X = S, Se) from their 2-formyl analogs. In the experiment, the researchers used many compounds, for example, 3-Bromo-2-methylbenzo[b]thiophene (cas: 10243-15-9Quality Control of 3-Bromo-2-methylbenzo[b]thiophene).
3-Bromo-2-methylbenzo[b]thiophene (cas: 10243-15-9) belongs to benzothiophene derivatives. Benzothiophene is used as starting material for the synthesis of bioactive molecules. The core structure is a part of various pharmaceutical substances and natural products. Its aromaticity makes it relatively stable, although as a heterocycle, it has reactive sites which allow for functionalization.Quality Control of 3-Bromo-2-methylbenzo[b]thiophene
Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem