Functional derivatives of thiophene. X. Synthesis of thieno[2,3-d]pyrimidine and 2,3-polymethylene-4-oxopyrimidine derivatives was written by Shvedov, V. I.;Kharizomenova, I. A.;Grinev, A. N.. And the article was included in Khimiya Geterotsiklicheskikh Soedinenii in 1975.Quality Control of 2-Amino-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylic acid This article mentions the following:
Thienopyrimidines [I, R1 = Me, H, R2 = Me, Ph, R1R2 = (CH2)4, n = 1,2,3] were prepared in 40.6-91.2% yields by boiling II (R3 = Et, H) with the appropriate lactam 20 min in dichloroethane containing POCl3. Desulfurization of I gave 48-65.4% III [R4 = CHMeEt, CHMePh, n = 1.2.3]. In the experiment, the researchers used many compounds, for example, 2-Amino-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylic acid (cas: 5936-58-3Quality Control of 2-Amino-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylic acid).
2-Amino-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylic acid (cas: 5936-58-3) 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 2-Amino-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylic acid
Referemce:
Benzothiophene – Wikipedia,
Benzothiophene | C8H6S – PubChem