Hydrochloric Acid → 4-Hydroxyphenylglycine

Participants

Reaction Steps

The supernatant solution obtained by centrifuging the reaction mixture was lyophilized, and the residue was extracted with ethanol. After removing insoluble materials by filtration, to the ethanol solution was added ethyl acetate in the weight ratio of ethyl acetate to ethanol of 2:1, and further added about 1.5 equivalents of dicyclohexylamine to give a white precipitate of dicyclohexylamine salt of N-carbamoyl-2-(4-hydroxyphenyl)glycine. The white precipitate was taken out, and was caused to react with 1.1 equivalents of sodium nitrite in an aqueous medium under acidic conditions with hydrochloric acid at room temperature for 1 hour. Then the resulting reaction mixture was passed through a column of a strongly acidic cation exchange resin of H-type (commercially available under the registered trademark "Amberlite IR-120B" made by Rohm & Haas Co.) to adsorb the produced 2-(4-hydroxyphenyl)glycine on the resin. After eluting with 1.5 N NH4OH, crystalline 2-(4-hydroxyphenyl)glycine was isolated by concentrating the eluate under reduced pressure. These procedures were repeated on each reaction mixture.

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