Citric Acid → HCID 23570950, compound

Participants

Reaction Steps

To a solution of 2-(3,4-dichloro-phenyl)-succinic acid 1-methyl ester (0.071 mol) in toluene (200 ml) at 0° C. were successively added diphenylphosphoryl azide (16.82 ml, 0.078 mol) and triethylamine (14.83 ml, 0.106 mol). The mixture was stirred at room temperature for 3 hours. The reaction mixture was diluted with 1% citric acid (100 ml) and extracted with EtOAc (3×150 ml). The combined organic extracts were washed with brine, dried (MgSO4) and concentrated in vacuo. The resulting oil was dissolved in tert-butanol (200 ml). Tin(IV) chloride (0.5 ml, 0.004 mol) was added and the mixture was heated to 80° C. for 1 hour (N2 evolving). The reaction mixture was cooled down to room temperature, quenched with a saturated solution of NaHCO3. Tert-Butanol was removed in vacuo and the mixture was extracted with EtOAc (3×150 ml). The combined organic extracts were washed with brine, dried (MgSO4) and concentrated in vacuo. The crude mixture was purified by silica gel column chromatography using as eluent petrol: EtOAc (9:1) to give the title compound (17.35 g) in 70% yield.). 1H NMR (400 MHz, DMSO-d6) δ 1.31 (9H, s), 3.25–3.40 (1H, m), 3.41–3.52 (1H, m), 3.61 (3H, s), 3.90 (1H, t), 6.95 (1H, t), 7.26 (1H, m); 7.52 (1H, s), 7.60 (1H, d); MS (ES+): m/e 348.2 (7%); MS (ES−): m/e=457.2 (100%), 459.2 (70%), 461.2 (15%).

Provenance & Evidence