6-(tert-Butyl)-5-methoxy-2-methyl-2,3-dihydro-1H-inden-1-one synthesis

Yield:952516-22-2 65%

Reaction Conditions:

with Eaton′s Reagent at 50 - 55; for 2 h;Cooling with ice;Time;Concentration;

Steps:

6-tert-Butyl-5-methoxy-2-methylindan-l-one (second experiment)

6-terf-Butyl-5-methoxy-2-methylindan-l-one (second experiment) To Eaton's reagent obtained from 118 g of P₄O₁₀ and 600 ml of methanesulfonic acid a mixture of 70.3 g (0.428 mol) of l-tert-butyl-2-methoxybenzene and 295.0 g (3.43 mol, 8 eqv.) of methacrylic acid was added for ca. 1 h at 50-55°C. The resulting mixture was stirred for 0.5 h at this temperature, then cooled to room temperature, and poured on a mixture of 1.5 liter of cold water and 2 kg of ice. After the ice melts, the precipitated crude 6-tert-butyl-5-methoxy-2-methylindan-l-one was filtered off and then washed with 2x100 ml of cold water. The crude product was dissolved in 500 ml of dichloromethane, and this solution was washed by aqueous K₂CO₃, dried over anhydrous K₂CO₃, and then evaporated on Rotavap. The residue was distilled in vacuum to give 70.6 g of crude 6-tert-butyl-5-methoxy-2- methylindan-l-one, b.p. 155-165°C/5 mm Hg. This product was dissolved in 200 ml of hot hexanes. Crystals precipitated from this solution at 5°C were collected, washed by 50 ml of cold hexanes, and dried in vacuum. This procedure gave 64.1 g (65%) of the analytically pure substituted indanone.

References:

WO2013/7650,2013,A1 Location in patent:Page/Page column 45; 46