Patent ID: 6930200

Claim:
A method for making a compound of Formula 1 where R 1 is selected from: (a) H, (b) mono-, di-, and tri-substituted aryl, and (c) C 1 -C 10 alkyl, C 1 -C 10 substituted alkyl, C 1 -C 10 substituted alkyl-aryl, C 1 -C 10 substituted alkenyl, and C 1 -C 10 substituted alkenyl aryl, and R 2 and R 3 are the same or different and are selected from (a) H, with the proviso that at least one of R 2 and R 3 is not H, and (b) C 1 -C 10 alkyl, C 1 -C 10 substituted alkyl, C 1 -C 10 substituted alkyl-aryl, C 1 -C 10 substituted alkenyl, and C 1 -C 10 substituted alkenyl aryl, and wherein R 2 and R 3 may be joined together to form a cyclic or heterocyclic ring having a ring size of 3 to 8 members. where the substituents of R 1 , R 2 , and R 3 are selected from: H, chloro, fluoro, bromo, iodo, nitro, cyano, amino, C 1 -C 10 alkyloxy, C 1 -C 10 alkyloxy aryl, C 1 -C 10 aminoalkyl, C 1 -C 10 alkylamino, C 1 -C 10 aminoalkyl aryl, C 1 -C 10 aminocarbonyl, C 1 -C 10 aminocarbonylalkyl-aryl, C 1 -C 10 thioalkyl, C 1 -C 10 thioalkyl-aryl, C 1 -C 10 alkylsulfoxide, C 1 -C 10 alkylsulfone, C 1 -C 10 alkylsulfonamide, C 1 -C 10 alkylsulfonamide aryl, C 1 -C 10 alkylsufoxide aryl, C 1 -C 10 alkylsulfone aryl, C 1 -C 10 alkyl, aminocarbonylamino C 1 -C 10 alkyl, C 1 -C 10 alky aminocarbonylamino C 1 -C 10 alkyl aryl, C 1 -C 10 alkyloxycarbonyl C 1 -C 10 alkyl, C 1 -C 10 alkyloxycarbonyl C 1 -C 10 alkyl aryl, C 1 -C 10 carboxyalkyl, C 1 -C 10 carboxyalkyl aryl, C 1 -C 10 carbonylalkyl, C 1 -C 10 carbonylalkyl aryl, C 1 -C 10 alkyloxcarbonylamino alkyl, C 1 -C 10 alkyloxycarbonylamino alkyl aryl, guanidino, C 1 -C 10 alkylCOOH, C 1 -C 10 alkylCONH 2 , C 1 -C 10 alkenylCOOH, C 1 -C 10 alkenyl CONH 2 , and where the aryl group of R 1 , R 2 , and R 3 is selected from: phenyl, biphenyl, 2-napthyl, 1-napthyl, pyridyl, furyl, thiophenyl, indolyl, isothiazolyl, imidazolyl, benzimidazolyl, tetrazolyl, pyrazinyl, pyrimidyl, quinolyl, isoquinolyl, benzofuryl, isobenzofuryl, benzothienyl, pyrazolyl, isoindolyl, purinyl, carbazolyl, isoxazolyl, thiazolyl, oxazolyl, benthiazolyl, benzoxazolyl; and where R 4 and R 5 are the same or different and are selected from: (d) H, and (e) an amine protecting group; said method comprising: (i) reacting a amino acid of the formula NH 2 —CHR—COOH or a salt thereof, wherein R is an aryl group selected from the group consisting of phenyl, biphenyl, 1-naphthyl, and 2-naphthyl, wherein the aryl group of R is substituted with 1 to 5 substituents selected from the group consisting of hydrogen, cyano, amino, C 1 -C 10 alky, C 1 -C 10 alkyloxy, C 1 -C 10 alkyloxyarl, C 1 -C 10 aminoalkyl, C 1 -C 10 alkylamino, C 1 -C 10 aminoalkyl aryl, a convertible isocyanide, and a compound of the formula R 3 —CO—R 2 , in an alcohol or an alcohol-containing solvent to obtain a compound of Formula 2 and (ii) subjecting the compound of Formula 2 to catalytic hydrogenation conditions, and to amide cleavage conditions, to obtain the compound of Formula 1.