DDQ in mechanochemical C-N coupling reactions

Shyamal Kanti Bera; Rosalin Bhanja; Prasenjit Mal

doi:10.3762/bjoc.18.64

DDQ in mechanochemical C-N coupling reactions

Beilstein J Org Chem. 2022 Jun 1:18:639-646. doi: 10.3762/bjoc.18.64. eCollection 2022.

Authors

Shyamal Kanti Bera^#¹, Rosalin Bhanja^#¹, Prasenjit Mal¹

Affiliation

¹ School of Chemical Sciences, National Institute of Science Education and Research (NISER), An OCC of Homi Bhabha National Institute, Bhubaneswar, PO Bhimpur-Padanpur, Via Jatni, District Khurda, Odisha 752050, India.

^# Contributed equally.

Abstract

2,3-Dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) is a commonly known oxidant. Herein, we report that DDQ can be used to synthesize 1,2-disubstituted benzimidazoles and quinazolin-4(3H)-ones via the intra- and intermolecular C-N coupling reaction under solvent-free mechanochemical (ball milling) conditions. In the presence of DDQ, the intramolecular C(sp²)-H amidation of N-(2-(arylideneamino)phenyl)-p-toluenesulfonamides leads to 1,2-disubstituted benzimidazoles and the one-pot coupling of 2-aminobenzamides with aryl/alkyl aldehydes resulted in substituted quinazolin-4(3H)-one derivatives in high yields.

Keywords: 1H-benzo[d]imidazole; C(sp2)–H amidation; DDQ; ball mill; mechanochemistry; quinazolin-4(3H)-one.

Grants and funding

SKB thank DST (INSPIRE) and RB thank CSIR (India) for fellowships.