Phenyl chloroformate → N,O-Bis-(phenoxycarbonyl)-hydroxylamine

Participants

Reaction Steps

To a 0° C. (ice bath) stirred sodium bicarbonate (143 g, 1.70 Mol ) solution (1 L H2O) in a 4 L Erlenmeyer flask was added hydroxylamine hydrochloride (58.76 g, 0.85 mol). After some foaming the reaction mixture was stirred for 0.5 h. Phenylchloroformate (400 g, :2.55 mol, 4×100 g bottles from Aldrich Chemical Company) was poured from the bottle directly into the vigorously stirred cold reaction mixture; rapidly followed by addition of additional sodium bicarbonate (214.5 g, 2.55 mol) in water (1.8 L ); 200 mL additional water used to rinse remaining bicarbonate residue into reaction mixture. The reaction was stirred 0.5 h the ice bath removed and stirred 2 h at room temperature. The resulting suspension was filtered and the collected white solid washed with water. The resulting wet white solid was collected, suspended in hexanes (800 mL), refiltered and collected; suspension in hexane, filtration was repeated two more times. The resulting solid was dissolved in ether (800 mL), washed with brine, dried (MgSO4), and concentrated to afford 200 g of the desired hydroxylamine derivative as a white solid. The material was dissolved in 450 mL ether with heating and hexanes were added (500 mL) with continued heating until some cloudiness develops. Seed crystals were added and product begins crystalization (precipitation); as solid forms more hexane was added (to a total volume of 1.8 L) and the flask allowed to stand overnight at room temperature. The mixture is then cooled to 5° and the white solid collected, washed with hexane, and dried to afford 175 g of white crystaline N,O-bis(carbophenoxy)hydroxylamine (75%). m.p.: 80°-82° C. 1H NMR (300 MHz, DMSO-d6) δ TMS: 7.16-7.14 (m, 10H), 12.35 (1H, bs). Anal. Calcd. for C14H11NO5 : C, 61.54; H, 4.06; N, 5.13. Found: C, 61.50; H, 4.14; N, 5.13.

Provenance & Evidence