Bromine → 6-(5-amino-[1,2,4]thiadiazol-3-ylthiomethyl)-3-tert-butoxycarbonyl-7-chloro-2,3,4,5-tetrahydro-1H-benzo[d]azepine

Participants

Reaction Conditions

Reaction Steps

To a solution of 3-tert-butoxycarbonyl-6-carbamimidoylthiomethyl-7-chloro-2,3,4,5-tetrahydro-1H-benzo[d]azepine hydrochloride (0.510 g, 1.256 mmol) in methanol (12.5 mL) at room temperature add solid sodium methoxide (0.14 g, 2.5 mmol) and then KSCN (0.12 g, 1.3 mmol). After cooling the reaction mixture to 0° C., add a solution of bromine (0.20 g, 1.3 mmol) in methanol (4 mL) dropwise. Stir the reaction mixture at room temperature overnight. Concentrate the reaction mixture in vacuo and partition the residue between DCM (100 mL) and water (50 mL). Extract the aqueous phase with DCM (50 mL). Dry the combined organic extracts over Na2SO4, filter and concentrate in vacuo. Dissolve the residue in DCM/methanol, add silica gel (5 g) and concentrate to a powder. Load the powder on to a dry column attached to a RediSep® column (40 g) and purify the crude mixture by preparative liquid chromatography (100:0 to 95:5 DCM/2M ammonia in methanol over 33 min; 95:5 to 80:20 DCM/2M ammonia in methanol over 33 min; 35 mL/min) to afford 6-(5-amino-[1,2,4]thiadiazol-3-ylthiomethyl)-3-tert-butoxycarbonyl-7-chloro-2,3,4,5-tetrahydro-1H-benzo[d]azepine (0.229 g, 43%). MS (ES+) m/z: 427.2 (M+H)+.

Provenance & Evidence