O-Xylene → HCID 19972556, compound

Participants

Reaction Steps

A mixture of 59.74 g of 3-methyl-8-chlorocarbonylflavone (obtained from 3-methylflavon-8-carboxylic acid and thionyl chloride, white crystals, m.p. 156°-156.5° C.), 200 ml of xylene, 6 g of 5% palladium on barium sulfate and 0.4 ml of quinoline-S, maintained under stirring and under hydrogen flow, was heated for 6-7 hours at 85°-90° C. Upon completion of the reaction, the mixture was cooled, diluted with chloroform (20 ml), filtered, the solvent was evaporated under vacuum, and 260 ml of 20% sodium hydrogensulfite (W/V) and 600 ml of water were added to the residue. The mixture thus obtained was heated at reflux for 2 hours and then filtered while hot. The cooled filtrate was extracted several times with ethyl ether (4×200 ml), concentrated hydrogen chloride added and then heated to 95°-100° C. for 2 hours. After cooling, the solid thus formed was filtered and washed with water. The product (II) was obtained in a global yield equal to 78% of theoretical (41.46 g) and could be used as such in further syntheses. After recrystallization from methyl-tert-butyl-ether, it melted at 124°-126° C.

Provenance & Evidence