1,2-Dibromoethane → Methyl 5-bromo-3-(2,2,2-trifluoroacetamido)thiophene-2-carboxylate

Participants

Reaction Steps

In reaction scheme 5 the synthesis of compound B53 is described. The intermediate 3-amino-5-bromo-thiophene-2-carboxylic acid methyl ester (compound B54b) is obtained according to a procedure described in literature (Bioorganic & Medicinal Chemistry Letters 17 (2007) 2535-2539) by conversion of methyl 3-aminothiophene-2-carboxylate to methyl 3-[(trifluoroacetyl)amino]thiophene-2-carboxylate with trifluoroacetic acid anhydride followed by a lithiation/bromination sequence using n-butyllithium and 1,2-dibromoethane to give methyl 5-bromo-3-[(trifluoroacetyl)amino]thiophene-2-carboxylate which is hydrolysed under basic conditions using potassium carbonate to obtain 3-amino-5-bromo-thiophene-2-carboxylic acid methyl ester (compound B54b).

Provenance & Evidence