Hydrochloric Acid → (2R)-1-[4-(1H-indol-4-yl)piperazin-1-yl]-N-methyl-3-pyridin-2-yl propan-2-amine

Participants

Reaction Steps

To a solution of (1R)-2-[4-(1H-indol-4-yl)piperazin-1-yl]-2-oxo-1-(pyridin-2-ylmethyl)ethylformamide (710 mg.; 1.9 mmol, from Example 19) in THF (10 mL) was added BF3.Et2O (0.47 mL; 3.8 mmol). The reaction mixture was heated to reflux, and treated, at reflux, with a 1M solution of BH3.THF in THF (19 mL; 19 mmol). Stirring was continued at reflux for 16 hours. The mixture was cooled to ambient temperature, cautiously treated with 5N aqueous HCl (20 mL), and heated to reflux for 4 hours. The mixture was cooled to ambient temperature and concentrated in vacuo to remove THF. The aqueous residue was washed with ether, and the ether layer discarded. The aqueous layer was rendered basic with 6N NaOH, and extracted with dichloromethane. The organic layer was dried over MgSO4, filtered, and the solvent removed in vacuo to afford the title compound as a white solid (110 mg.; 17%). MS (+) ESI [M+H]+ @ m/z 350.

Provenance & Evidence