Ammonium Chloride → 4-(4-Fluorobenzoyl)-3-(hydroxymethyl)benzonitrile

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

1048 g of a 10% solution of 4-fluorophenylmagnesium bromide in tetrahydrofuran are added to a suspension of 60.0 g of 5-cyanophthalide in 390 ml of 1,2-dimethoxyethane at −10° C. within three hours. After stirring for 30 minutes at −10° C., the cold reaction mixture is poured into 1 L of aqueous NH4Cl (180 g in 1000 ml of water, 20° C.) in about 5 minutes. The layers are separated and the aqueous layer is extracted with 300 ml of tetrahydrofuran. The organic layers are combined and volatiles are removed under reduced pressure at 45° C. The residue is dissolved in a mixture of 1000 mL of CH2Cl2 and 200 ml of water containing 2.5 g of sodium carbonate (pH of 9). The layers are separated and the organic phase is dried with 40 g of sodium carbonate. The dry CH2Cl2 solution is treated with 6 g of charcoal, stirred for 10 minutes and the charcoal is removed by filtration. The filter cake is washed with 50 mL of CH2Cl2. Filtrate and washing liquid are combined and the solvent is removed under reduced pressure. 300 mL of diisopropylether are added to the residue. After stirring for 1 hour at 22° C. the crystal suspension is cooled to 0° C. and stirred for another two hours, then cooled to −10° C. and stirred for 14 hours. The product is isolated by filtration and washed with 40 mL of chilled diisopropylether, 80 mL of a 1:1 mixture of diisopropylether/cyclohexane and 80 mL of cyclohexane. After drying for 3 hours at 50° C. in vacuo 83.0 g (86.2% of theory, purity (HPLC): 99.8 area %) white, crystalline powder of the title compound are obtained (mp. 85° C.).

Herkunft & Nachweise