Trifluoroacetic acid → 7-chloro-6-[3-(3,3-dimethyl-2-oxo-2,3-dihydro-1H-indol-5-yl)-propylthio]-2,3,4,5-tetrahydro-1H-benzo[d]azepine

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Reaction Steps

Add trifluoroacetic acid (0.2 mL, 2.6 mmol) to a solution of 3-tert-butoxycarbonyl-7-chloro-6-[3-(3,3-dimethyl-2-oxo-2,3-dihydro-1H-indol-5-yl)-propylthio]-2,3,4,5-tetrahydro-1H-benzo[d]azepine (257 mg, 0.5 mmol) in dichloromethane (5 mL) then stir at ambient temperature over the weekend. Concentrate in vacuo. Dissolve the residue in methanol and load onto an SCX column. Elute with methanol followed by 7M ammonia in methanol. Collect the basic fraction and concentrate in vacuo. Purify the residue by prep-LCMS [Supelco Discovery C18 column (21.2×100 mm, 5 μm packing), 25 mL/min flow rate, eluting with a water/acetonitrile gradient containing acetic acid as modifier over 12 min, fraction collection triggered by Electrospray MS] to give 7-chloro-6-[3-(3,3-dimethyl-2-oxo-2,3-dihydro-1H-indol-5-yl)-propylthio]-2,3,4,5-tetrahydro-1H-benzo[d]azepine as a white solid (101 mg, 25% over 2 steps). MS (ES+) m/z: 415 (M+H)+.

Provenance & Evidence