Hydrochloric Acid → 3-Isoquinolinecarboxylic acid,1,2,3,4-tetrahydro-6-hydroxy-,hydrochloride

Participants

Reaction Steps

To a mixture of 100.0 g of 3-hydroxyphenylalanine in 820 ml of 5% hydrochloric acid were added 78 ml of formaldehyde (37% in water). The reaction mixture was heated at 90°-95° C. (external bath temperature) for 45 minutes. The mixture was cooled and concentrated in vacuo. Five hundred milliliters of ethanol were added and the mixture was again concentrated in vacuo, affording 115 g of the title intermediate as a pale white solid, used without purification in the next step.

Provenance & Evidence