Synthesis 2020; 52(22): 3480-3484
DOI: 10.1055/s-0040-1707344
paper
© Georg Thieme Verlag Stuttgart · New York

Scalable Synthesis of 3-Ethyl-4-methyl-1,5-dihydro-2H-pyrrol-2-one: An Important Building Block of the Antidiabetic Drug Glimepiride

a   Division of Organic Chemistry, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India   Email: sp.chavan@ncl.res.in
b   Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
,
Ambaji A. Pawar
a   Division of Organic Chemistry, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India   Email: sp.chavan@ncl.res.in
b   Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
,
Niteen B. Patil
a   Division of Organic Chemistry, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India   Email: sp.chavan@ncl.res.in
b   Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
,
Appasaheb L. Kadam
a   Division of Organic Chemistry, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India   Email: sp.chavan@ncl.res.in
b   Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
,
Shrikrishna S. Shinde
a   Division of Organic Chemistry, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India   Email: sp.chavan@ncl.res.in
› Author Affiliations
A.A.P. and A.L.K. thank the University Grants Commission (UGC), New Delhi and N.B.P. thanks the Council of Scientific and Industrial Research (CSIR), New Delhi for the award of research fellowships. The authors thank CSIR, New Delhi for financial support as part of the XII Year Plan Programme under title ORIGIN (CSC-0108) and ACT (CSC-0301).
Further Information

Publication History

Received: 18 February 2020

Accepted after revision: 25 June 2020

Publication Date:
04 August 2020 (online)


Abstract

A four-step, practical, and easily scalable synthesis of 3-ethyl-4-methyl-1,5-dihydro-2H-pyrrol-2-one, an important building block of the antidiabetic drug glimepiride, has been accomplished. Key features are the synthesis of 3-methyl-4-hydroxy-2-butenolide in water and triflic acid mediated N-benzyl lactam N-deprotection. The main advantages of this process are the scalable synthetic route and decreased number of reaction steps, which paves the way for the industrial-scale synthesis of 3-ethyl-4-methyl-1,5-dihydro-2H-pyrrol-2-one.

Supporting Information