Resorcinol → 7-hydroxy-2,3-dihydro-4H-chromen-4-one

Participants

Reaction Steps

Under ice cooling, AlCl3 (3 molar equivalent) was added little by little to a solution composed of 11 g of resorcinol, 12.7 g of 2-chloropropionyl chloride and 120 ml of nitrobenzene. After the addition, the mixture was heated at 40° to 50° C. for 4 hours with stirring. The reaction mixture was worked up and purified in a customary manner to give 4.1 g of 2,3-dihydro-7-hydroxy-4-oxobenzopyran. The resulting compound was benzylated, reduced with sodium borohydride in methanol, and then methylated with methyl iodide in tetrahydrofuran in the presence of sodium hydride. In a customary manner, the methylated product was hydrogenated to give 1.7 g (yield 9.4%) of the desired product as a colorless liquid.

Provenance & Evidence