Formaldehyde → 1,2,3,4-Tetrahydro-6-hydroxy-3-isoquinolinecarboxylic acid

Participants

Reaction Conditions

Reaction Steps

To 61.5 g of D, L-m-tyrosine suspended in 250 ml of 0.05N sulfuric acid aqueous solution, 48 ml of 37% formalin aqueous solution was added dropwise. The reaction mixture was stirred at 70° C. for 12 hours, and subjected to crystallization under ice cooling for 2 hours. The obtained crystal were filtered off, and dried at 60° C. under reduced pressure to obtain 65.6 g of Compound 1 (yield 100%). Compound 1 thus obtained was dissolved in an aqueous solution of 2N sodium hydroxide, and was then adjusted to pH 5 with concentrated hydrochloric acid. The precipitate was filtered off, washed with water and dried at 60° C. under reduced pressure to obtain 52.5 g of purified product of Compound 1.

Provenance & Evidence