A solution of 8-bromo-4,5-dihydro-6-oxa-1-thia-benzo[e]azulene-2-carboxylic acid (25 g, 0.077 mol) in 200 mL of SOCl2 was heated at 80° C. for 3 h. Concentration gave the crude acid chloride. A suspension of the crude acid chloride (ca. 0.077 mol) from above in 1000 mL of THF at 0° C. was treated with a solution of 3-amino-4-chloro-benzoic acid methyl ester (15.7 g, 1.1 eq)/pyridine (30 mL) in 100 mL of THF. The mixture was allowed to reach room temperature overnight. The reaction solution was concentrated to 1/2 volume, diluted with water. The resulting precipitate was filtered, washed with water and Et2O. The filter cake was dried to a constant weight under vacuum to give methyl 3-(8-bromo-4,5-dihydrobenzo[b]thieno[2,3-d]oxepine-2-carboxamido)-4-chlorobenzoate (32.9 g, yield 87%). LC-MS: (ESI, m/z)=494 [M+1]+
