Studies on the Synthesis of Novel Chiral Naphthylene Bisoxazoline Ligands

Abstract

The synthesis of chiral C ₂-symmetric substituted bisoxazoline ligands containing naphthalene group were investigated. Ethyl 2,3-naphthylene-dicarboxylate reacted with amino alcohols and the resulting amides were treated with SOCl₂ and then reacted with Et₃N in toluene to afford the desired bisoxazolines. 2,3-Naphthylenedicarbonitrile reacted with amino alcohol give N- (1′-phenyl-2′-hydroxyethyl)-2,3-naphthylenedicarboximide 1. The 2,3-naphthylenedicarboxylic acid reacted with thionyl chloride give the 2,3-Naphthalenedicarboxylic acid cyclic anhydride rather than corresponding 2,3-naphthalenedicarboxylic acid dichloride, the former reacted with amino alcohol also give compound 1. The later two strategies cannot give the target bisoxazoline.

Keywords:

• Bisoxazoline
• Naphthylene
• Synthesis
• Amino alcohol

Acknowledgment

This work was supported by the National Natural Science Foundation of China (Grant No. 20172001). Visiting Scholar from Wenzhou Medical College, Wenzhou, Zhejiang, P.R. China.