Diethyl Oxalate → HCID 71254945, compound

Participants

Reaction Steps

Ethyl 4-(3-chloro-2-fluorophenyl)-3-methyl-2,4-dioxobutanoate: To the solution of LiHMDS (1 M in THF) (3.19 mL, 3.19 mmol) in ether (12 mL) at −78° C. was added dropwise a solution of Intermediate 47B (0.59 g, 3.16 mmol) in ether (2 mL). After 45 min., diethyl oxalate (0.492 mL, 3.60 mmol) was added in one portion, and the reaction was warmed to rt. After 18 h, the reaction mixture was filtered, washing with ether. The filtrate was diluted with EtOAc, washed with 1 N HCl, brine, dried over Na2SO4, filtered and concentrated. Purification by silica gel chromatography yielded the desired product (0.057 g, 6%) as a yellow oil. MS(ESI) m/z: 241.0 (M-OEt)+. 1H NMR (500 MHz, CDCl3) δ 7.80 (ddd, J=8.0, 6.3, 1.7 Hz, 1H), 7.65 (ddd, J=7.8, 7.0, 1.9 Hz, 1H), 7.23 (td, J=8.0, 0.8 Hz, 1H), 4.91 (q, J=7.2 Hz, 1H), 4.31 (qd, J=7.2, 0.8 Hz, 2H), 1.46 (dd, J=7.2, 0.8 Hz, 3H), 1.34 (t, J=7.2 Hz, 3H) ppm.

Provenance & Evidence