A New Approach to the Enantioseparation of Betti Bases

Abstract

An improved method for enantioseparation of racemic 1-(a-aminobenzyl)-2-naphthols has been developed by the reaction in situ of Betti base product mixtures with L-(+)-tartaric acid taken in a 1:1 ratio. The products of this reaction are (-)-1-(a-aminobenzyl)-2-naphthol tartrate, the acetal of benzaldehyde and tartaric acid as well as (+)-1,3-diaryl-2,3-dihydro-1H-naphth[1,2-e][1,3]oxazine, which can be easily separated by crystallization.

Selective Synthesis and Structural Confirmation of 1,3‐Oxazines and Schiff Bases with Controllable Substitution Patterns

“…[34] Compound 4 a is a polymorph of a previously reported structure (VEYSIC) with a P2 1 space group. [35] The conformations of both the structures are similar with a root-meansquare deviation of 0.3 . The molecular interactions are described in Table 3.…”

1‐(α‐Aminobenzyl)‐2‐naphthol: A New Chiral Auxiliary for the Synthesis of Enantiopure α‐Aminophosphonic Acids

“…[7] In the present work, we demonstrate the potential of these readily available Betti adducts as chiral inductors for the synthesis of enantiopure a-aminophosphonates.…”

Syntheses, transformations and applications of aminonaphthol derivatives prepared via modified Mannich reactions

“…The products of this reaction were (S)-3a tartrate, the acetal of benzaldehyde and tartaric acid, and (þ)-2a, which were easily separated by crystallization (Scheme 1). 22 Harrison et al recently reported the syntheses of 6-bromosubstituted aminonaphthol derivatives (9aen) from 6-bromo-2-naphthol (7), methanolic ammonia and the corresponding aromatic aldehyde. The naphthoxazine intermediates 8aen were hydrolysed with hydrochloric acid to yield the desired aminonaphthol derivatives 9aen (Scheme 3).…”