Methane → 6-(3-Chloro-4-fluorobenzoyl)-1-oxa-6-azaspiro[2.5]octane-2-carbonitrile

Participants

Reaction Conditions

Reaction Steps

A suspension of 1-(3-chloro-4-fluorobenzoyl)piperidin-4-one (4160 g, 16.27 mol) in 28.4 liters of dichloromethane and 11.7 liters of sodium hydroxide at 30.5%, supplemented with 186 g of tetrabutylammonium chloride, is cooled to 15° C. Chloroacetonitrile (1540 ml, 24.4 mol) is then added slowly and with vigorous stirring and the mixture is stirred for 3 hours at 20° C. Further addition of chloroacetonitrile (500 ml) is carried out in order to complete the reaction. The reaction medium is diluted with dichloromethane (8.5 liters) and water (20 liters) and then separated by decantation and washed again with water. The brown solution obtained is decolorized with 2 kg of silica and 500 g of animal charcoal and then evaporated to dryness. The residue obtained is crystallized from isopropanol in order to give, after filtration, 3426 g of brown crystals. m.p.=100–101° C.

Provenance & Evidence