Dimedone → HCID 22461273, compound

Participants

Reaction Steps

Methyl 4,4-dimethyl-3-oxopentanoate (20 g, 0.13 mol) and AcOH (48 mL) were cooled to 10° C. and a solution of NaNO2 (12.3 g, 0.19 mol) in water (48 mL) was added dropwise to the stirred mixture, maintaining the temperature below 20° C. After addition the mixture was warmed to room temperature and stirred for 2 h. The mixture was then extracted with DCM (3×100 mL). The combined organic layers were evaporated and the residue taken up in ether. The ethereal layer was washed with water (100 mL), separated and dried (Na2SO4). The resultant yellow gum (22.7 g, 96%) was used without further purification. 1H NMR (250 MHz, CDCl3) δ 1.23 (9H,s), 3.89 (3H,s), 9.00-10.00 (1H,br s). Sodium acetate trihydrate (20.6 g, 0.15 mol) and 5,5-dimethyl-1,3-cyclohexandione (16.9 g, 0.12 mol) in propionic acid (140 mL) were heated to 150° C. A solution of the oxime (22.7 g, 0.12 mol) in propionic acid (70 mL) was added via a dropping funnel, whilst simultaneously adding zinc dust (12 g) over 20 min. The solution was heated at reflux for 24 h after which time it was poured into water. The resultant solid was collected by filtration then triturated with ether. The colourless solid (3.7 g, 14%) was collected by filtration. 1H NMR (360 MHz, CDCl3) δ 1.10 (6H,s), 1.35 (9H,s), 2.35 (2H,s), 2.64 (2H,s), 6.43 (1H,d,J=2.2 Hz), 7.80-8.14 (1H,br s). MS (ES+) 220 (M+1).

Provenance & Evidence