Hydrochloric Acid → 3,3-Diethyl-1-hydroxy-1,3-dihydrobenzo[c][1,2]oxaborole-5-carbaldehyde

Participants

Reaction Steps

To a solution of 3,3-diethyl-5-methylbenzo[c][1,2]oxaborol-1(3H)-ol (2.0 g, 9.8 mmol) in CCl4 (25 ml) at rt was added benzoyl peroxide (237 mg, 0.98 mmol) followed by NBS (3.489 g, 19.6 mmol). The reaction mixture was refluxed for 16 h, cooled to rt and treated with aqueous Na2CO3. The aqueous layer was acidified with 3N HCl to pH=3 and extracted with EA (50 ml×3). The organic layer was washed with brine, dried over Na2SO4, filtered and concentrated under reduced pressure to give the desired product (1.2 g, yield 56%) as white solid. 1H NMR (300 MHz, DMSO-d6): δ 10.06 (s, 1H), 9.30 (s, 1H), 7.85 (m, 3H), 1.86 (m, 4H), 0.55 (m, 6H). MS: m/z=219 [M+1]+.

Provenance & Evidence