Efficient synthesis of novel imidazo[1,2-a]pyrimidine derivatives via one-pot three-component procedure

Samahe Sadjadi,Fatemeh Nahavandi,Majid Heravi

doi:10.1007/s13738-014-0564-x

Abstract

Synthesis of novel derivatives of imidazo[1,2-a]pyrimidine from one-pot three-component reaction of aldehydes, 2-amino-benzimidazole, and α-tetralone in the presence of catalytic amount of p-toluene sulfonic acid under reflux condition in EtOH has been presented. The simplicity and safety of the process, high yields and short reaction times were the main advantages of this protocol.

Highlights

Multi-component reactions (MCRs) involving at least three starting materials in a one-pot reaction have gained much attention in modern organic chemistry
Synthesis of imidazo[1,2-a]pyrimidines via condensation of 2-aminopyrimidine with α-halocarbonyl compounds has been developed. The drawback of this method is difficulty in preparation, purification, toxicity, and lachrymatory property of α-halocarbonyl compounds which limit its reliability. Taking this fact into account, developing an efficient and simple route for synthesis of imidazo[1,2-a] pyrimidines is of great interest [19,20,21,22,23,24]
In our efforts to use MCRs in the synthesis of heterocycles [25–27], we present a multi-component and efficient route for the synthesis of novel imidazo[1,2-a] pyrimidines from the reaction of aldehydes, 2-amino-benzimidazole, and α-tetralone in the presence of catalytic amount of p-toluene sulfonic acid (Scheme 1)

Summary

Introduction

Multi-component reactions (MCRs) involving at least three starting materials in a one-pot reaction have gained much attention in modern organic chemistry. The most common synthetic methods reported for the preparation of imidazo[1,2-a]pyrimidine ring systems involve closure of the imidazole ring by the condensation of 2-aminopyrimidine and closure of the pyrimidine ring by the condensation of 2-aminoimidazole with appropriate electrophilic compounds. Synthesis of imidazo[1,2-a]pyrimidines via condensation of 2-aminopyrimidine with α-halocarbonyl compounds has been developed. The drawback of this method is difficulty in preparation, purification, toxicity, and lachrymatory property of α-halocarbonyl compounds which limit its reliability. Taking this fact into account, developing an efficient and simple route for synthesis of imidazo[1,2-a] pyrimidines is of great interest [19,20,21,22,23,24]. In our efforts to use MCRs in the synthesis of heterocycles [25–27], we present a multi-component and efficient route for the synthesis of novel imidazo[1,2-a] pyrimidines from the reaction of aldehydes, 2-amino-benzimidazole, and α-tetralone in the presence of catalytic amount of p-toluene sulfonic acid (Scheme 1)

Experimental procedures

Results and discussion

Conclusion