Patent ID: 6414180
Filing Date: 2002-07-02
Classification: C07C

Abstract:
A process for the preparation of chiral &bgr;-amino acids of the formula wherein X and Y are the same or different halo group; wherein R2 is H or lower alkyl which process comprises reacting a 3,5-dihalosalicylaldehyde of the formula with MEMCl to produce a protected 3,5 dihalosalicylaldehyde of the formula where P is MEM;treating the protected 3,5-dihalosalicylaldehyde with (R) or (S) phenylglycinol in THF or toluene to produce an imino alcohol of the formula reacting said imino alcohol with BrZnCH2CO2-t-Bu in NMP, DMSO or THF to produce an amino alcohol of the formula reacting the amino alcohol with lead tetraacetate, sodium periodate or periodic acid to produce an imine of the formula transesterifying, deprotecting and hydrolyzing said imine and isolating a chiral product of the formula â€ƒor an acid addition salt thereof.