Hydrochloric Acid → Ethyl 2-(6-(5-amino-1,3,4-thiadiazol-2-yloxy)-1-hydroxy-4-methyl-1,3-dihydrobenzo[c][1,2]oxaborol-3-yl)acetate

Participants

Reaction Conditions

Reaction Steps

Concentrated aq. HCl (50 mL) and water (1000 mL) were added to a mixture of ethyl 2-(1-hydroxy-4-methyl-6-(5-nitro-1,3,4-thiadiazol-2-yloxy)-1,3-dihydrobenzo[c][1,2]oxaborol-3-yl)acetate (70 g, 0.18 mol) and iron powder (51 g, 0.9 mol) in ethanol (3000 mL) at room temperature. The resulting mixture was stirred at 85° C. for 2 hrs, cooled to room temperature and filtered through a pad of celite. The filtrate was evaporated and the residue dissolved in EtOAc, washed with brine, dried over Na2SO4 and concentrated to give compound ethyl 2-(6-(5-amino-1,3,4-thiadiazol-2-yloxy)-1-hydroxy-4-methyl-1,3-dihydrobenzo[c][1,2]oxaborol-3-yl)acetate (40 g, 63% yield) which was used without further purification. 1H NMR (400 MHz, DMSO-d6) δ 9.30 (1H, s), 7.32 (1H, m), 7.16 (1H, m), 7.15 (2H, s), 5.50 (1H, m), 4.03 (2H, m), 3.08 (1H, m), 2.32 (4H, m), 1.10 (3H, m).

Provenance & Evidence