Ethyl isobutyrate → HCID 11482859, compound

Participants

Reaction Steps

Under N2 atmosphere, a solution of LDA (2.0 M in heptane/THF/ethylbenzene, 2.94 L, 5.9 mol) was added dropwise to a stirred solution of ethyl isobutyrate (720 g, 6.2 mol) in anhydrous THF (4.7 L) at −45° C. After 1 h, 1,6-dibromohexane (2400 g, 9.8 mol) was added dropwise, followed by the addition of DMPU (320 mL). The reaction mixture was stirred for 1 h and then allowed to warm to room temperature overnight. Saturated NH4Cl solution (3 L) was added and the mixture was extracted with ethyl acetate (3×6 L). The combined organic layers were washed with brine (4.5 L), 1 M aqueous HCl (6 L), saturated NaHCO3 solution (6 L), and brine (4.5 L). The solution was dried over anhydrous MgSO4 and concentrated in vacuo. The residue was distilled under high vacuo to furnish 205i (856 g, 52%) as a light yellowish oil. Bp 95-100° C./0.2 mmHg. 1H NMR (CDCl3): δ (ppm): 4.13 (q, J=7.1, 2 μl), 3.39 (t, J=6.9, 2 H), 1.92-1.75 (m, 2H), 1.58-1.25 (m, 8H), 1.25 (t, J=7.1, 3 H), 1.12 (s, 6H). 13C NMR (CDCl3=77.52 ppm): δ (ppm): 177.62, 60.01, 42.08, 40.50, 33.63, 32.68, 29.13, 27.93, 25.00, 24.66, 14.22. HRMS (LSIMS, nba): Calcd for C12H24BrO2 (MH+): 279.0960, found: 279.0957. GC: 76.4% pure.

Provenance & Evidence