3-Bromo-6-methoxychroman-4-one → HCID 20153986, compound

Participants

Reaction Steps

A mixture of 3-bromo-6-methoxy-4-chromanone (2.57 g) and 3.3 g of the ethylene ketal of 1-(propylamino)-2-propanone in 500 ml of toluene if refluxed for 17 hours. The resulting product is dissolved in 20 ml of nitromethane and added to 50 ml of 85% polyphosphoric acid. After 48 hours at room temperature the reaction is poured onto ice to afford 2,3,4a,5-tetrahydro-9-methoxy-4-propyl-4H-[1]-benzopyrano[3,4-b]pyridin-2-one.

Provenance & Evidence