Phosphorus oxychloride → HCID 43805572, compound

Participants

Reaction Conditions

Reaction Steps

A stirred mixture of 4-bromo-2-chlorobenzoic acid (2 g, 8.49 mmol) and hydrazinecarbothioamide (1.161 g, 12.74 mmol) was cooled under nitrogen in an ice-bath. POCl3 (2.375 mL, 25.5 mmol) was then added dropwise. On completion of addition, the reaction mixture was warmed to 78° C. and left to stir for 3 hours. The reaction mixture was allowed to cool to room temperature then cooled further in an ice-bath. Quenching by addition of ice-water (50 mL) resulted in a solid/gum-like mass. This material was sonicated for 1.5 hours and the resulting suspension was diluted with a further 50 mL water and slurried for 16 hours. The suspension was filtered under vacuum and the solid rinsed with water, then re-suspended in saturated NaHCO3(aq) (100 mL). The suspension was slurried for 30 minutes then filtered under vacuum and rinsed with water to afford the crude product as an off-white solid. The crude product was pre-absorbed onto silica gel and purified by flash chromatography using a gradient from 0-10% MeOH/DCM over 30 minutes to afford the title compound as a pale yellow/off-white solid (1.087 g, 44% yield). LC-MS: Rt 1.09 min; MS m/z 292.0 [M+2H]+ [Method A]. 1H NMR (400 MHz, DMSO-d6) δ ppm 7.96 (d, J=8.59 Hz, 1H), 7.91 (d, J=2.02 Hz, 1H), 7.68 (dd, J=8.59, 2.02 Hz, 1H), 7.51 (s, 2H).

Provenance & Evidence