US 7,521,579 B2
Process for the preparation of alpha hydroxycarboxylic acid amides
Martin Zeller, Muenchwilen (Switzerland); Dominik Faber, Muenchwilen (Switzerland); Thomas Vettiger, Basel (Switzerland); and Clemens Lamberth, Basel (Switzerland)
Assigned to Syngenta Crop Protection, Inc., Greensboro, N.C. (US)
Appl. No. 10/495,257
PCT Filed Nov. 15, 2002, PCT No. PCT/EP02/12844
§ 371(c)(1), (2), (4) Date May 07, 2004,
PCT Pub. No. WO03/042166, PCT Pub. Date May 22, 2003.
Claims priority of application No. 0127559.3 (GB), filed on Nov. 16, 2001.
Prior Publication US 2005/0014950 A1, Jan. 20, 2005
Int. Cl. C07C 233/05 (2006.01); C07C 231/02 (2006.01)
U.S. Cl. 564—170  [564/134; 564/139; 564/140] 15 Claims
 
1. A process for the preparation of 2-phenyl-2-hydroxy-N-[2-(3-alkoxy-4-hydroxyphenyl)-ethyl]-acetamides of the formula I

OG Complex Work Unit Drawing
wherein R1 is alkyl,
R2, and R3 are each independently hydrogen or alkyl, and
R4, is optionally substituted aryl or optionally substituted heteroaryl, which process comprises reacting a nitrostyrene of the formula IV

OG Complex Work Unit Drawing
wherein R1, R2 and R3 are as defined above, with reducing agent to form a 2-phenyl-nitroethane derivative of the formula V,

OG Complex Work Unit Drawing
wherein R1 R2 and R3 are as defined above; and further reacting this intermediate 2-phenyl-nitroethane derivative of the formula V with hydrogen in the presence of a catalyst to obtain a 2-(3-alkoxy-4-hydroxyphenyl)-ethylamine of the formula II

OG Complex Work Unit Drawing
wherein R1 R2 and R3 are as defined above, and reacting it with a α-hydoxycarboxylic acid ester of the formula III or a dioxolanone of the formula IIIa

OG Complex Work Unit Drawing
wherein R4 is as defined above, and R5, R6 and R7 independently of each other are lower alkyl.