Diethyl Oxalate → HCID 57433879, compound

Participants

Reaction Steps

The product from Example 57A (11.80 g, 56.6 mmol) in THF (200 mL) at −78° C. was treated with n-butyllithium (30 mL, 75.0 mmol, 2.5M in hexanes) dropwise. After 30 minutes, the mixture was treated with diethyl oxalate (25.0 mL, 184 mmol). After 20 minutes, the solution was allowed to warm to room temperature and was treated with saturated NH4Cl (150 mL). The mixture was concentrated under reduced pressure. The residue was treated with dichloromethane (100 mL) filtered, and the filtrate concentrated under reduced pressure. The residue was purified by column chromatography (20% ethyl acetate/hexanes) to provide the title compound as light brown oil (4.57 g, 35%). MS (ESI+) m/z 248 (100), 230 (M+H)+, (ESI−) m/z 200 (M−Et)−; 1H NMR (DMSO-d6, 300 MHz) rotomers δ 1.26 (t, J 7.1, 0.6H), 1.37 (t, J 7.1, 2.4H), 4.21 (q, J 7.1, 0.4H), 4.47 (q, J 7.1, 1.6H), 7.89 (t, J 7.5, 1H), 8.41 (dd, J 1.0, 7.5, 1H), 8.57 (d, J 8.1, 1H), 8.64 (d, J 5.7, 1H), 8.73 (d, J 6.3, 1H), 9.50 (s, 1H).

Provenance & Evidence