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Paramétrages

Paramétrages

1. WO1985002609 - PREPARATION DE PHENYL ALANINES PAR HYDROGENATION DE PHENYL SERINES

Note: Texte fondé sur des processus automatiques de reconnaissance optique de caractères. Seule la version PDF a une valeur juridique
C l a i m s

1. Process for the preparation of phenyl alanine derivatives of the general formula

wherein

R stands for hydrogen or C1-4 alkyl
R5 stands for hydrogen or -CO-R4 wherein
R4 stands for hydrogen, C1-4 alkyl, aryl or aralkyl which c o m p r i s e s reacting a phenyl serine derivative of the general formula



or a salt thereof formed with an inorganic or organic acid - wherein
R is as defined above
R 2 stands for hydrogen or -CO-R4 - wherein
R4 is as defined above -with hydrogen in the presence of a catalyst and
optionally N-acylating said product.

2. Process for the preparation of phenyl alanine, which c o m p r i s e s reacting 3-phenyl serine with hydrogen in the presence of a catalyst and a
protic solvent and 1-5 moles of mineral acid calculated for 3-phenyl serine.
3. Process as claimed in claim 1, which
c o m p r i s e s using metal palladium as catalyst, preferably in the form of 10-50 % by weight of 10 % palladium on charcoal related to the weight of the
starting material.
4. Process as claimed in claims 1-2, which
c o m p r i s e s conducting the reaction by introducing hydrogen gas at 1-10 atm. and 20-120 ºC in the presence of 1-5 moles of mineral acid and protic solvent. 5. Process as claimed in claims 1-3, which
c o m p r i s e s carrying out the reaction in the presence of a protic solvent, such as C1-4 alcohol,
C1-4 straight carboxylic acid, water or a mixture thereof, preferably in glacial acetic acid.
6. Process as claimed in claims 1 to 2, which c o m p r i s e s forming the required hydrogen in situ from a substance releasing hydrogen in the reaction mixture on the surface of the catalyst.
7. Process as claimed in claim 5, which
c o m p r i s e s using hydrazine, cyclohexene or cyclohexadiene as a hydrogen releasing agent.

8. Process as claimed in claims 1 to 2 and 5, which c o m p r i s e s using formic acid as hydrogen releasing substance.
9. Process as claimed in claims 1, 2, 5 and 7, for the preparation of N-formyl-phenyl-alanine of the general formula



which c o m p r i s e s reacting phenyl serine of the formula



with 2-20 moles formic acid related to phenyl serine in the presence of 40 % by weight of 10 % palladium on charcoal related to the weight of phenyl serine.
10. Process as claimed in claim 1, which c o m p r i s e s reacting phenyl serine or a salt thereof with at least 3 moles of formic acid related to phenyl serine in the presence of palladium on charcoal catalyst and after removing the catalyst reacting the obtained N-formyl-phenyl-alanine with water and mineral acid by method known per se in order to produce a salt of phenyl alanine formed with mineral acid.
11. Process as claimed in claims 1 to 8, which c o m p r i s e s using as starting material - preferably without isolation - a 3-phenyl serine prepared from glycine and benzaldehyde under alkaline conditions in the presence of a phase transfer catalyst and a two-layer organic solvent, one of which consists of a water inmiscible organic solvent and the other one consists of water miscible organic solvent and/or water.
12. Process as claimed in claim 9, which
c o m p r i s e s using as a two-layer system water or a mixture of water and C1-4 alkanol as one layer and aromatic hydrocarbon, preferably benzene or toluene as the other layer.
13. Process as claimed in claims 8 to 9, which c o m p r i s e s using 0.01-1.0 mole equivalent quaternary ammonium salt related to glycine as phase transfer catalyst at 15-100 °C, preferably at 25-40 °C.