US 7,321,055 B2
Production method of optically active dephenylalanine compounds
Takayuki Hamada, Kawasaki (Japan); Masayuki Oshita, Kawasaki (Japan); and Masanobu Yatagai, Kawasaki (Japan)
Assigned to Ajinomoto Co., Inc., Tokyo (Japan)
Filed on Aug. 04, 2006, as Appl. No. 11/498,752.
Claims priority of application No. 2005-227077 (JP), filed on Aug. 04, 2005.
Prior Publication US 2007/0032658 A1, Feb. 08, 2007
Int. Cl. C07C 229/00 (2006.01)
U.S. Cl. 562—441  [562/401; 562/402; 546/136] 26 Claims
 
1. A method of producing an optically active diphenylalanine compound represented by formula (3):

OG Complex Work Unit Drawing
wherein R1 and R2 are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted amino group, a nitro group, a hydroxyl group, or a protected hydroxyl group, each n is independently an integer of 1 to 5, P1 is an amino-protecting group, * indicates an asymmetric carbon atom, and the configuration of each asymmetric carbon atom is S or R,
which method comprises:
(i) reacting a diphenylalanine compound represented by formula (1):

OG Complex Work Unit Drawing
wherein R1 and R2 are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted amino group, a nitro group, a hydroxyl group, or a protected hydroxyl group, each n is independently an integer of 1 to 5, and P1 is an amino-protecting group, with an optically active amine compound represented by formula (2):

OG Complex Work Unit Drawing
wherein R3 is a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a hydroxyl group, a protected hydroxyl group, a cyano group, a nitro group, or an acyl group, or two adjacent R3 are optionally condensed to form a benzene ring, n is an integer of 1-5, * indicates an asymmetric carbon atom, and the configuration of each asymmetric carbon atom is S or R; and
(ii) separating the resulting diastereomeric salt.