Methanol → Phenyl(2-phenyl-4,7-dihydro-2H-1,3-dioxepin-2-yl)methanone

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Reaction Steps

60.8 g (1.9 mols) of methanol were added with stirring to a suspension of 105 g (0.5 mol) of benzil in 107.1 g (0.9 mol) of thionyl chloride, with cooling to a temperature below 10° C. The mixture was initially stirred until room temperature was reached, and then it was stirred for 2 hours at 50° C. 52.8 g (0.6 mol) of cis-2-butene-1,4-diol were added to the clear, pale yellow solution, and volatile products were distilled off at 10 torr and 50° C. The mixture was then stirred for 3 hours at from 60° to 65° C. under normal pressure, 15 g of potassium carbonate and 200 ml of isopropanol were added, and the reaction product was precipitated by the dropwise addition of 100 ml of water. 110.4 g of 2-benzoyl-2-phenyl-4,7-dihydro-1,3-dioxepin were obtained, having a melting point of from 115° to 119° C. After recrystallizing from isopropanol, the melting point was from 118° to 119° C.

Provenance & Evidence