L-Phenylalanine → 4-Aminophenylalanine

Temperatur

5 °C

L-Phenylalanine was converted to 4-nitro-L-phenylalanine by a conventional nitration process known in the art. Thereafter, about 100 g of 4-nitro-L-phenylalanine was dissolved in about 600 mL of about 3.5% methanolic sodium hydroxyide solution and hydrogenated by hydrogen gas at a pressure of about 45 psi in the presence of a 5% palladium/carbon catalyst with the pH of the solution being about 11. The temperature of the reaction mixture was maintained from about 20° C. to about 40° C. The reaction mixture was periodically monitored for the completion of reaction by use of HPLC analysis. The reaction mixture was then filtered to remove the palladium/carbon catalyst and neutralized to about pH 7 with acetic acid. The neutralized filtrate was cooled to about 5° C., until 4-amino-L-phenylalanine precipitated out. The precipitate was isolated by filtration, washed with methanol and dried. (Weight 76 g, HPLC Purity 98%.)

1. temperatureThe temperature of the reaction mixture was maintained from about 20° C. to about 40° C
2. customThe reaction mixture was periodically monitored for the completion of reaction by use of HPLC analysis
3. filtrationThe reaction mixture was then filtered
4. customto remove the palladium/carbon catalyst
5. customprecipitated out
6. customThe precipitate was isolated by filtration
7. washwashed with methanol
8. customdried

ORD-Eintrag

ord-5d442a654d3445ecbd6a288bb65a2e74

Quelldatensatz

uspto-grants-2013_11

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08575385B2