Borane → Trifluoroacetic acid

Participants

Reaction Steps

To a solution of methyl 3-(4-fluorobenzylcarbamoyl)-5-(4-fluorophenoxy)benzoate (2.7 g, 6.79 mmol) in 10 mL of THF at ice bath temp was added borane (40 mL of 1 M solution in THF) slowly. After 10 min, the mixture was warmed to rt, stirred for 30 min and heated at 50° C. for 10 h. The mixture was cooled to rt and treated with 10 mL of 1M solution of LiAlH4 in THF. The mixture was stirred for 2 h and treated with EtOAc. The resulting mixture was treated with MeOH and TFA slowly, stirred for a while, mostly concentrated. Water and MeOH were added to the residue and the insoluble material was filtered. The filtrate was concentrated. Purification of the residue using prep HPLC provided the desired product as a white solid of TFA salt (1.74 g, 54.6%). 1H NMR (CD3OD): δ 7.49˜6.97 (m, 11H), 4.56 (s, 2H), 4.19 (s, 2H), 4.16 (s, 2H); MS (ESI): (M+H)+=356.24.

Provenance & Evidence