Pyridine → HCID 58831675, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of the azide, Compound 4 (prepared essentially by the method of Hruby et al., J. Org. Chem. 2002, 67, 3514-3517) (2.0 g, 7.6 mmol, 1 equiv) in dichloromethane at 23° C. (20 mL), was added pyridine (920 μL, 11.5 mmol, 2.5 equiv), followed by phenyl chloroformate (1.05 mL, 8.35 mmol, 1.1 equiv). After 1 h the resulting suspension was partitioned between dichloromethane (50 ml) and aqueous hydrochloric acid (2N, 50 mL). The organics were dried over sodium sulfate and concentrated in vacuo. To the resultant residue was added THF (20 mL), water (2 mL) and triphenylphosphine (2.2 g, 8.35 mmol, 1.1 equiv). The resulting solution was heated to 50° C. for 1 h, during which time gas evolution was observed. The reaction was diluted with dichloromethane (100 mL) and sodium sulfate was added to the resultant solution. The organics were filtered and concentrated in vacuo. The residue was purified by flash chromatography on silica gel, gradient elution (40-50-60-70% ethyl acetate in hexanes) to give the oxazolidinone, Compound 5 (1.85 g, 7.1 mmol, 93%) as a colorless solid mp=99-101° C., Rf=0.29 (50% ethyl acetate in hexanes), [α]23D−12.5 (c 1.15, CHCl3); FTIR (neat), cm−1: 3288, 2971, 1762, 1739, 1214; 1H NMR (500 MHz, CDCl3), δ: 7.37 (m, 5H), 5.71 (bs, 1H), 5.22 (ABO, 2H, J=12 Hz), 4.37 (m, 1H), 1.76 (m, 1H), 0.97 (d, 3H, J=6.5 Hz), 0.92 (d, 3H, J=7 Hz); 13C NMR (100 MHz, CDCl3), δ: 169.4, 159.5, 134.6, 128.7, 128.6, 128.6, 67.6, 58.0, 29.0, 18.7, 18.4. LRMS Calcd for C14H17NO4 [M]+ 263.1. Found [M+NH4]+ 281.2.

Provenance & Evidence