Phosphorus oxychloride → 5-(2-Chloro-4-iodophenyl)-1,3,4-thiadiazol-2-amine

Participants

Reaction Conditions

Reaction Steps

A stirred mixture of 2-chloro-4-iodobenzoic acid (2 g, 7.08 mmol) and hydrazinecarbothioamide (0.968 g, 10.62 mmol) was cooled under nitrogen in an ice bath. POCl3 (1.98 mL, 21.24 mmol) was added drop-wise and the reaction mixture was heated at 78° C. for 3 hours. The reaction mixture was cooled in an ice bath before quenching by addition of ice water (50 mL). The resulting solid/cake was sonicated for 1 hour to give a free stirring suspension. This material was left to slurry at room temperature for ˜18 hours then filtered under vacuum and rinsed with water to afford the crude product as a pale yellow/orange solid. The solid was re-suspended in saturated NaHCO3(aq) (50 mL), slurried at room temperature for 2 hours, then collected by vacuum filtration to afford the title compound as a pale yellow solid (2.05 g, 86% yield). LC-MS: Rt 1.20 min; MS m/z 337.8 [M]+ [Method A]. 1H NMR (400 MHz, DMSO-d6) δ ppm 8.01 (d, J=1.52 Hz, 1H), 7.76-7.82 (m, 2H), 7.50 (s, 2H).

Provenance & Evidence