Dichloromethane → 2-Methoxy-7-oxo-6,7,8,9-tetrahydro-5H-benzocycloheptene-6,8-dicarboxylic acid diethyl ester

Participants

Reaction Steps

From an adapted procedure in Helvetic Chimica Acta, 2001, 84, 2051-2063, to a stirred solution of Tetra-n-butylammonium iodide (12.1 g, 0.0326 mol) in 0.6 M of Sodium bicarbonate in Water (300 mL) and Methylene chloride (130 mL, 2.1 mol) was added a solution of 1,2-Bis-bromomethyl-4-methoxy-benzene (16.00 g, 0.05442 mol) and 3-Oxopentanedioic acid, diethyl ester (14.31 g, 0.07075 mol) in Methylene chloride (40 mL, 0.6 mol). The solution was stirred vigorously at room temperature for 20 h. Saturated ammonium chloride solution was added to the reaction mixture. The product was extracted with ethyl acetate (3×100 mL). The ethyl acetate extracts were washed with water and brine, then dried over magnesium sulfate, filtered and concentrated in vacuo to a yellow oil. The oil was triturated with ether and a precipitate crashed out of solution and was removed by filtration (tetrabutylammonium salts). The filtrate was concentrated to an oil (20.0 grams, 100%) that was carried on to the next step without further purification.

Provenance & Evidence