5-Nitro-benzo[b]thiophene-2-carboxylic acid methyl ester

Synthesis

General procedure for the synthesis of methyl 5-nitrobenzo[b]thiophene-2-carboxylate from methyl mercaptoacetate and 2-chloro-5-nitrobenzaldehyde: To a solution of 2-chloro-5-nitrobenzaldehyde (3.7 g, 0.020 mol) in N,N-dimethylformamide (40 mL) was added methyl mercaptoacetate (1.82 mL, 0.020 mol), followed by potassium carbonate ( 3.3 g, 0.024 mol). The reaction mixture was stirred at room temperature overnight. After completion of the reaction, water was added to the mixture and the suspension was filtered. The solid residue was washed with water to afford the target product methyl 5-nitrobenzo[b]thiophene-2-carboxylate as a yellow solid. Yield: 95%.

References

[1] Synthetic Communications, 1991, vol. 21, # 7, p. 959 - 964
[2] Organic and Biomolecular Chemistry, 2015, vol. 13, # 24, p. 6814 - 6824
[3] Patent: WO2006/101454, 2006, A1. Location in patent: Page/Page column 45
[4] Patent: EP2876105, 2015, A1. Location in patent: Paragraph 0945; 0946
[5] Heterocycles, 2008, vol. 75, # 8, p. 1913 - 1929