Synthesis and applications of Chiral Aminonaphthols, Amino Alcohols and Amines

Abstract

This thesis describes, ?Synthesis and Applications of Chiral Aminonaphthols, Amino Alcohols and Amines?. It comprises of three chapters. 1) Introduction, 2) Results and Discussion and 3) Experimental Section. The work described in this thesis is exploratory in nature. The first chapter describes a brief review on the preparation as well as applications of chiral aminonaphthols, amino alcohols and amine derivatives in various organic transformations. The second chapter deals with the results and discussion on the synthesis of aminonaphthols, amino alcohols and amines for application in resolution, reductions, and hydroboration studies. A convenient method was developed for the synthesis of aminonaphthols 3 by straightforward condensation of and#946;-naphthol 1, benzaldehyde 2 and 1o or 2o amines in ethanol at 78 oC for 6-12 h (Scheme 1). Scheme 2 A simple and convenient methodology for the synthesis of aliphatic aminonaphthols using the readily accessible 1-acetyl-2-naphthol 6 as precursor was developed (Scheme 3). Racemic 1-(and#945;-pyrrolidinylbenzyl)-2-naphthol 3a was resolved using inexpensive L- newline(+)-tartaric acid 11 in acetone through formation of diastereomeric complexes (Scheme 4). The chiral aminonaphthol S-(+)-3a was used for the resolution of racemic 1,1and#8242;-bi-2- newlinenaphthol. We have observed that the readily accessible aminonaphthol 12 is useful for the resolution of racemic ibuprofen 13 and mandelic acid 14. Racemic ibuprofen 13 was resolved in acetone, whereas mandelic acid 14 gave good results in CH3CN solvent (Scheme 5 and 6). These partially resolved samples were further enriched to obtain samples with 97% Preparation of (S)-2-diphenylpyrrolidinemethane 16 was carried out in a single step by the reduction of (S)-2-diphenylpyrrolidinemethanol 15 with trifluroacetic acid and sodium borohydride...