Hydrochloric Acid → HCID 71572008, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of (E)-1-hydroxy-3,3-dimethyl-1,3-dihydrobenzo[c][1,2]oxaborole-5-carbaldehyde oxime (200 mg, 0.98 mmol) in DMF (7 mL) at rt was added NCS (157 mg, 1.17 mmol). The reaction mixture was warmed to 45° C., stirred for 2.5 h and cooled to rt. This mixture was added dropwise to a solution of 2-chloro-1,3-difluoro-5-(3,3,3-trifluoroprop-1-en-2-yl)benzene (237 mg, 0.98 mmol) and TEA (218 mg, 2.16 mmol) in DMF (7 mL) at 0° C. The mixture was stirred at this temperature for 1 h, and then at rt overnight. The mixture was acidified with 3 N HCl to pH of 2, then poured into water and extracted with EA (50 mL×2). The combined organic layers were washed with brine, dried over Na2SO4, filtered and concentrated under reduced pressure. The residue was purified by prep-TLC (PE:EA=2:1) to give the final title compound (150 mg, yield 35%) as white solid. 1H NMR (300 MHz, DMSO-d6): δ 9.24 (s, 1H), 7.82-7.73 (m, 3H), 7.71-7.60 (m, 2H), 4.50 (d, J=18.3 Hz, 1H), 4.44 (d, J=18.3 Hz, 1H), 1.51 (s, 3H), 1.50 (s, 3H) ppm; HPLC purity: 95.5% at 214 nm and 97.8% at 254 nm; MS: m/z=446 (M+1, ESI+).

Provenance & Evidence