Boron tribromide → 3-(Biphenyl-4-ylsulfonyl)-1,3-thiazolidine-2-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

A solution was made containing Intermediate 6, e.g., methyl 3-([1,1′-biphenyl]-4-ylsulfonyl)-1,3-thiazolidine-2-carboxylate (2.0 g, 5.5 mmol, 1 eq), in dry DCM (50 ml). The flask was cooled down to −20° C. in a dry-acetone bath. A solution of boron tribromide (5.55 g, 22.0 mmol) in dry DCM (30 ml) was added drop wise over a period of 10 minutes. The reaction mixture was stirred for 1 h at 0° C. The reaction mixture was diluted with DCM (50 ml) and washed with a 1M HCl solution (2×50 ml) and with brine (50 ml) before drying over magnesium sulfate, filtering and removal of solvent in vacuo. The desired product of general structure (VIII), e.g., 3-([1,1′-biphenyl]-4-ylsulfonyl)-1,3-thiazolidine-2-carboxylic acid, was isolated as a white powder (1.8 g, 94%).

Provenance & Evidence