High-yielding method for preparation of carbocyclic or N-containing heterocyclic β-keto esters using in situ activated sodium hydride in dimethyl sulphoxide. Issue 1 (2nd January 2016)

• Record Type: Journal Article
• Authors: Popović-Djordjević, Jelena; Stepanović, Stepan; Došen-Mićović, Ljiljana; Ivanović, Evica; Ivanović, Milovan D.
• Is Part Of: Green chemistry letters and reviews. Volume 9:Issue 1(2016)
• Page Start: 61
• Page End: 68
• Publication Date: 2016-01-02
• Subjects: Acylation -- condensation reaction -- environmentally benign solvent; Green chemistry -- Periodicals; 540
• DOI: 10.1080/17518253.2016.1145744
• Languages: English
• ISSNs: 1751-8253

Abstract

ABSTRACT: It was found that NaH suspension in DMSO was highly activated when reacted with an alcohol. The in situ generated NaH/alkoxide mixture permitted very rapid and complete deprotonation and acylation of various cyclic ketones with alkyl carbonates at ambient temperature. Activated NaH/alkoxide in DMSO is particularly effective in Dieckmann condensations, where it affords 5- and 6-membered carbocyclic or N -containing heterocyclic β-keto esters in high yields. A heterocyclic Dieckmann condensation was performed on a molar scale, demonstrating the scalability of the procedure. Besides, DMSO is non-toxic, relatively inexpensive and environmentally benign solvent. GRAPHICAL ABSTRACT: