HIGHLY EFFICIENT SYNTHESIS OF 2,4-DISUBSTITUTED OXAZOLES THROUGH PALLADIUM/COPPER COMEDIATED DIRECT ARYLATION REACTION

Venkata Reddy Regalla; Rama Krishnam Raju Addada; Venkat Swamy Puli; Abhishek S Saxena; Anindita Chatterjee

doi:10.22159/ajpcr.2018.v11i8.26125

Authors

Venkata Reddy Regalla Department of Chemistry, Koneru Lakshmaiah University, Vaddeswaram, Guntur, Andhra Pradesh, India.
Rama Krishnam Raju Addada Department of Chemistry, Koneru Lakshmaiah University, Vaddeswaram, Guntur, Andhra Pradesh, India.
Venkat Swamy Puli Department of Chemistry, Koneru Lakshmaiah University, Vaddeswaram, Guntur, Andhra Pradesh, India.
Abhishek S Saxena GVK Biosciences Private Limited, Medicinal Chemistry Division, 28A, IDA, Nacharam, Hyderabad, Telangana, India.
Anindita Chatterjee Department of Chemistry, Koneru Lakshmaiah University, Vaddeswaram, Guntur, Andhra Pradesh, India.

DOI:

https://doi.org/10.22159/ajpcr.2018.v11i8.26125

Keywords:

Oxazoles, Arylation, Palladiumcopper

Abstract

Objective: The aim of the present study is to synthesize 2,4-disubstituted oxazoles through palladium/copper comediated direct arylation reaction.

Methods: 2,4-disubstituted oxazoles (3a-i) have been synthesized by the reaction of 4-substituted oxazole with aryl bromide in the presence of KOH , CuI and Pd(PPh3)4 in dimethoxyethane. Titled compounds (3a-i) were obtained in good yields using an expedient two-step synthesis of 2,4-disubstituted oxazoles from commercially available starting materials

Results: The structures of the newly synthesized compounds were characterized by Fourier-transform infrared, 1H NMR, 13C NMR, and mass spectral studies. This method can be an efficient method for the synthesis of 2,4-disubstituted oxazoles (3a-i).

Conclusion: Pd(PPh3)4 and CuI cocatalytic system direct arylation of 4-aryl/alkyl oxazoles with various aryl bromides has been developed to generate 2,4-disubstituted oxazoles. The high functional group tolerance and the speed of the reaction afford this method appropriate for the combinatorial synthesis of a variety of 2,4-disubstituted oxazoles.

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