Cyanogen Bromide → 5-[6-[(4-tert-Butylphenyl)sulfonyl]-2-(trifluoromethyl)-6,11-dihydro-5H-pyrido[2,3-b][1,5]benzodiazepin-8-yl]-1,3,4-oxadiazol-2-amine

Participants

Reaction Steps

To a solution of 6-[(4-tert-butylphenyl)sulfonyl]-2-(trifluoromethyl)-6,11-dihydro-5H-pyrido[2,3-b][1,5]benzodiazepine-8-carbohydrazide (intermediate 57, 0.040 g, 0.0771 mmol) and NaHCO3 (7 mg in 0.187 mL of water) in dioxane (0.75 mL) was added cyanogen bromide (9 mg in 0.084 mL of dioxane) was in four equal portions over 5 min. After stirring at rt for 2 h, the reaction was quenched with saturated aqueous NaHCO3 and the product was extracted with EtOAc and DCM. The combined extracts were washed with brine, dried (MgSO4) and concentrated. The residue was purified by SiO2 column chromatography to provide the title compound. LC/MS: m/e 545.1 (M+H)+. 1H NMR (500 MHz, CD3OD): δ 7.78 (1H, s), 7,76 (1H, d, J=8.5 Hz), 7.67 (1H, d, J=3.6 Hz), 7.63 (1H, d, J=7.3 Hz), 7.07-7.13 (3H, m), 6.91 (1H, d, J=8.5 Hz), 4.6-4.9 (2H, br), 3.53 (3H, s), 1.22 (9H, s).

Provenance & Evidence