104145-72-4

Upstream product

• 104145-71-3 2-hydroxy-3-(2-nitro-phenyl)-propionic acid 
• 504-03-0 2.6-dimethylpiperidine 

Downstream Products

• 104145-74-6 (+)-α-Chloro-2-aminobenzenepropanoic acid, 2,6-dimethylpiperidine salt 

Relevant academic research and scientific papers

Process for the asymmetric synthesis of chiral indoline-2-carboxylic acids

Disclosed herein is a process for producing an asymmetric indoline-2-carboxylic acid of the structural Formula: STR1 wherein X is hydrogen, bromine, chlorine, C1-4 alkyl or C1-4 alkoxy, which comprises: (a) assymetrically reducing an o-nitrophenylpyruvic acid III by contacting the acid III with a reducing complex formed from (R)-proline or (S)-proline, respectively, and sodium borohydride in an inert solvent to form, respectively, an (S) or (R)-α-hydroxy-2-nitrobenzenepropanoic acid IV; (b) reacting, respectively, said (S) or (R)-α-hydroxy-2-nitrobenzenepropanoic acid III with a Vilsmeier chlorinating reagent in which the chlorinating agent thereof is selected from a group consisting of thionyl chloride, oxalyl chloride, phosphorus oxychloride, phosphorus pentachloride and sulfuryl chloride and the amide thereof is selected from a group consisting of dimethylformamide, diethylformamide, dimethylacetamide and diethylacetamide, said reaction being run at temperatures of at least 20° C., in order to obtain, respectively, and (R) or (S)-α-chloro-2-nitrobenzenepropanoic acid IV; (c) reducing the nitro group of said (R) or (S)-α-chloro-2-nitrobenzenepropanoic acid (V) to an amino group; and (d) cyclizing the resulting (R) or (S)-α-chloro-2-aminobenzenepropanoic acid in aqueous base.

Process for preparing indoline-2-carboxylic acids via alpha-hydroxy-2-nitrobenzenepropanoic acid

Disclosed herein is a process for obtaining indoline-2-carboxylic acid (or derivatives thereof) comprising the following steps: (a) reducing α-oxo-2-nitrobenzenepropanoic acid to α-hydroxy-2-nitrobenzenepropanoic acid, (b) replacing the hydroxyl group of the latter with a chlorine atom utilizing a selected Vilsmeier chlorinating reagent at temperatures of at least 20° C., (c) reducing the nitro group of the resulting α-chloro-2-nitrobenzenepropanoic acid to obtain α-chloro-2-aminobenzenepropanoic acid, and (d) cyclizing the latter in aqueous base to form the desired indoline-2-carboxylic acid. Alternately, steps (c) and (d) may be combined in a one pot step by using, for example, a Raney nickel-hydrazine reducing medium.