131175-70-7

Upstream product

• 85-44-9 phthalic anhydride 
• 56613-61-7 (R)-4-nitro-phenylalanine 
• 100-14-1 4-nitrobenzyl chloride 
• 855633-22-6 (4-nitro-benzyl)-phthalimido-malonic acid diethyl ester 
• 101445-16-3 N-(2-carboxy-benzoyl)-4-nitro-phenylalanine 
• 60666-01-5 (RS)-N-phthaloyl-p-nitrophenylalanine 

Downstream Products

• 6957-95-5 4-nitro-N,N-phthaloyl-D-phenylalanin-ethyl ester 
• 178421-54-0 (2R,3S)-N-tert-Butyl-2-(1,3-dioxo-1,3-dihydro-isoindol-2-yl)-3-hydroxy-3-(4-nitro-phenyl)-propionamide 
• 178421-56-2 (R)-N-tert-Butyl-2-(1,3-dioxo-1,3-dihydro-isoindol-2-yl)-3-(4-nitro-phenyl)-propionamide 
• 177719-67-4 (2S,3S)-3-bromo-N-phthaloyl-p-nitrophenylalanine methyl ester 
• 178899-25-7 (2S,3R)-3-bromo-N-phthaloyl-p-nitrophenylalanine methyl ester 
• 135635-69-7 (2R,3S)-2-amino-3-hydroxy-3-(4-nitrophenyl)propionic acid 
• 178601-75-7 (R)-N-phthaloyl-p-nitrophenylalanine methyl ester 

Relevant academic research and scientific papers

Neighbouring group effects promote substitution reactions over elimination and provide a stereocontrolled route to chloramphenicol

In reactions of β-brominated valine and p-nitrophenylalanine derivatives to give β-hydroxy amino acid derivatives the carboxyl group, when protected as an amide, exerts a neighbouring group effect to facilitate the substitution process, and reduce competing elimination reactions. As a consequence of the effect, the (2R,3R)- and (2R,3S)-stereoisomers of 3-bromo-N-tert-butyl-N(α)-phthaloyl-p-nitrophenylalaninamide both react to give (2S,3R)-3-hydroxy-N-tert-butyl-N(α)-phthaloyl-p-nitrophenylalaninamid e, providing a stereoconvergent route to chloramphenicol.