Methyl Thioglycolate → 5-Bromo-benzo(b)thiophene-2-carboxylic acid

Participants

Reaction Steps

In a similar manner to Example 9 Method A, 1-(benzo[b]thiophen-5-yl)propan-1-one was prepared starting from methyl thioglycolate (13.2 g) and 5-bromo-2-fluorobenzaldehyde (25.35 g) which were reacted together and the product hydrolysed to give 5-bromobenzo[b]thiophene-2-carboxylic acid (30.4 g), which was decarboxylated using copper and quinoline at 190° C. for 1.5 hours to give 5-bromobenzo[b]thiophene. This compound was reacted with magnesium and then with N-methoxy-N-methylpropionamide to give 1-(benzo[b]thiophen-5-yl)propan-1-one (1.3 g) as a cream solid which was used without further purification.

Provenance & Evidence