29843-09-2

Upstream product

• 90-82-4 rac-pseudoephedrine 
• 100-52-7 benzaldehyde 
• 299-42-3 ephedrine 
• 321-98-2 (1S,2R)-(+)-ephedrine 
• 100-47-0 benzonitrile 

Downstream Products

• 128257-18-1 (R)-N-Methyl-1-phenylpropylamine 
• 5933-40-4 (R)-(+)-N,α-dimethylbenzylamine 

Relevant academic research and scientific papers

From solution to in-cell study of the chemical reactivity of acid sensitive functional groups: A rational approach towards improved cleavable linkers for biospecific endosomal release

pH-Sensitive linkers designed to undergo selective hydrolysis at acidic pH compared to physiological pH can be used for the selective release of therapeutics at their site of action. In this paper, the hydrolytic cleavage of a wide variety of molecular structures that have been reported for their use in pH-sensitive delivery systems was examined. A wide variety of hydrolytic stability profiles were found among the panel of tested chemical functionalities. Even within a structural family, a slight modification of the substitution pattern has an unsuspected outcome on the hydrolysis stability. This work led us to establish a first classification of these groups based on their reactivities at pH 5.5 and their relative hydrolysis at pH 5.5 vs. pH 7.4. From this classification, four representative chemical functions were selected and studied in-vitro. The results revealed that only the most reactive functions underwent significant lysosomal cleavage, according to flow cytometry measurements. These last results question the acid-based mechanism of action of known drug release systems and advocate for the importance of an in-depth structure-reactivity study, using a tailored methodology, for the rational design and development of bio-responsive linkers.

Comparison of Conventional and Microwave Assisted Reactions Giving Aromatic Oxazolidines

By reaction of aromatic aldehydes with (-)-ephedrine aromatic 1,3-oxazolidines can be obtained. The reaction was carried out either at conventional conditions or by microwave heating. The different diastereomeric ratios were determined by means of 1

Heterogeneous rhodium-catalyzed hydrogenation conditions for the highly effective synthesis of 1,3-oxazolidines from 1,2-amino alcohols and nitriles

A procedure easily to carried out for the synthesis of 1,3-oxazolidines in high yields using 1,2-amino alcohols, nitriles, an atmospheric pressure of hydrogen and catalytic quantities of rhodium on carbon powder is presented. This reaction probably involves the semi-hydrogenation of the nitrile followed by condensation with the amine alcohol. The process may constitute the key step in a two-step sequence for reducing a nitrile into the corresponding aldehyde.

Formation of azomethine ylids by thermolysis of oxazolidines. Study of the reaction in solution and in the gaseous phase

Thermolysis of oxazolidines leads to azomethine ylids via cycloreversion.In the liquid phase, these intermediates then give 1-3 dipolar cycloaddition; in the gaseous phase, they lead to aziridines.With an alkyl group in position 2, we observed also the formation of enamines.The effect of substituents on both the cycloreversion reaction and the evolution of azomethine ylids was studied.The mechanism of the process tautomerism aziridine -> azomethine ylid -> enamine is discussed.Keywords - azomethine ylids / oxazolidines / cycloreversion / aziridines / enamines / tautomerism

STEREOCHEMISTRY-60 KINETIC CONTROL OF ASYMMETRIC INDUCTION DURING OXAZOLIDINE FORMATION FROM (-)-EPHEDRINE AND AROMATIC ALDEHYDES

Kinetically controlled oxazolidine formation was observed with aromatic aldehydes substituted by electron-withdrawing groups.The stereoselectivity is solvent dependent: non-stereoselective ring closure occurred in chloroform while a high diastereodifferentiation was observed in methanol.The first oxazolidine showing an unambiguous 2R configuration was synthesized from p-bromobenzaldehyde and (-)-ephedrine in alcohol medium.A mechanism involving a nucleophilic assistance by alcoholic solvents is suggested in order to clarify the differences in stereoselectivity.

Role of Solvent on the Diastereoselectivity of Oxazolidine Formation from (-)-Ephedrine

Under kinetic control, the stereochemical course of the condensation between (-)-ephedrine and p-cyano- or p-nitro-benzaldehyde is solvent dependent; no noticeable stereoselectivity was observed in chloroform whereas diastereo-differentiation occurred in methanol.