5-Ethyl-1,2-oxazol-3-amine → N-(5-ethyl-1,2-oxazol-3-yl)-1-oxo-2,3,4,5-tetrahydro-1H-[1,4]diazepino[1,2-a]indole-8-carboxamide

Participants

Reaction Steps

To a solution of 1-oxo-2,3,4,5-tetrahydro-1H-[1,4]diazepino[1,2-a]indole-8-carboxylic acid (Intermediate J, 75 mg, 0.31 mmol) in THF (2 mL) and DMF (0.5 mL) is added HATU (128 mg, 0.34 mmol). The mixture is stirred at room temperature for 1 h, after which polystyrene bound 2-tert-butylimino-1,3-dimethylperhydro-1,3,2-diazaphosphorine (419 mg, 0.92 mmol) is added. The mixture is stirred at room temperature for 10 min and 5-ethyl-3-aminoisoxazole (103 mg, 0.92 mmol) is added. The reaction is stirred at 60° C. for 16 h and is then cooled to room temperature. The mixture is filtered, washing with methanol and the filtrate is concentrated under reduced pressure. The residue is purified via preparative HPLC using a gradient elution from 10-90% acetonitrile/water with 0.1% TFA to obtain the title compound (5 mg, 5%). LCMS: 339.20 (M+H+). (System V1)

Provenance & Evidence