79199-61-4

Upstream product

• 78-79-5 isoprene 
• 139334-63-7 ethyl (2R)-4-methyl-1-((S)-1-phenylethyl)-1,2,3,6-tetrahydropyridine-2-carboxylate 
• 1350815-39-2 (2R,4S)-ethyl 4-methyl-1-((S)-1-phenylethyl)piperidine-2-carboxylate 
• 139334-62-6 (6R)-1-<(R)-1-phenylethyl>-6-ethoxycarbonyl-4-methyl-3,4-didehydropiperidine 
• 134984-62-6 (2R,4S)-4-Methyl-1-((R)-1-phenyl-ethyl)-piperidine-2-carboxylic acid ethyl ester 

Relevant academic research and scientific papers

Method of resolving argatroban starting material isomer impurities

The invention provides a method of resolving argatroban starting material isomer impurities. The method includes: with ethyl 4-methyl-2-piperidinecarboxylate racemate as a raw material and L-(-)-dibenzoyltartaric acid as a resolving agent, salifying to obtain ethyl (2R,4S)-4-methyl-2-piperidinecarboxylate-L-(-)-dibenzoyltartrate shown as a compound I, freeing the compound I under alkaline conditions to obtain ethyl (2R,4S)-4-methyl-2-piperidinecarboxylate shown as a compound II. The method provided herein is simple to perform, and has total resolving yield of 45.2% and post-resolving chiral purity of 99.2%.

Diastereoselective synthesis of an argatroban intermediate, ethyl (2R,4R)-4-methylpipecolate, by means of a Mandyphos/rhodium complex-catalyzed hydrogenation

The synthetic antithrombotic argatroban is a dipeptide between the nonproteogenic (2R,4R)-4-methyl-2-piperidine carboxylic acid and l-arginine, in turn bonded to a methyltetrahydroquinoline sulfonyl group. An extensive screening of transition metal-based complexes with different ligands was performed in order to identify the best catalyst for the diastereoselective hydrogenation of a suitable 4,5-dehydropiperidine precursor aimed toward a synthesis of the (2R,4R)-4-methyl piperidine moiety. Copyright

Enantio- and Diastereo-selective Synthesis of Pipecolic Acid Derivatives using the Aza-Diels-Alder Reaction of Imines with Dienes

Optically active pipecolic acid derivatives can be prepared by the aza-Diels-Alder reaction of simple dienes with the imine derived from ethyl glyoxylate and chiral 1-phenylethylamine; the cycloadditions are regiospecific, highly diastereoselective within the heterocyclic ring (>92percent exo with cyclic dienes, and 100percent endo with acyclic dienes), and lead to high asymmetric induction in most cases (average d.e. = 72percent).