Toluene → Diethyl 2-acetyl-2-methyloctanedioate

Participants

Reaction Steps

In a 1 L three necked flask equipped with a mechanical stirrer and reflux condenser was placed dry toluene (300 ml). The system was flushed with argon and sodium hydride (Aldrich, 60% dispersion in mineral oil) (7.2 g, 0.18 mmol) was added. Ethyl-γ-methylacetoacetate (Aldrich, 21 g, 0.15 mole) was added with stirring over a 30 minutes. The resulting solution was heated under reflux for 2 hrs and cooled slightly. (Note: Reaction mixture becomes a thick paste and mechanical stirrer is essential). Ethyl 6-bromohexanoate (Aldrich, 33.5 g, 0.15 mol) was added (all at once) and the suspension was heated under reflux for 12 hrs, cooled, filtered and the solvent evaporated under pressure. The residue was distilled under vacuum to yield 20 g (46%) of colorless liquid, b.p. 110-115° C. (0.1 mm). IR (neat): σcm−1=1735 (s) and 1713 (s). 1H NMR in CDCl3 δ, 4.1-4.2 (m, 4H, (O—CH2)2); 2.1 (t, J=8.4 Hz, 2H, CH2COO—); 2.15 (s, 3H, CH3CO); 1.5-2.0 (m, 4H, (CH2)2); 1.2-1.4 (m, 13H, 2 CH2 and three —CH3).

Provenance & Evidence