Optimized synthesis of aroyl- S,N-ketene acetals by omission of solubilizing alcohol cosolvents

Julius Krenzer; Thomas J J Müller

doi:10.3762/bjoc.21.97

Optimized synthesis of aroyl- S,N-ketene acetals by omission of solubilizing alcohol cosolvents

Beilstein J Org Chem. 2025 Jun 20:21:1201-1206. doi: 10.3762/bjoc.21.97. eCollection 2025.

Authors

Julius Krenzer¹, Thomas J J Müller¹

Affiliation

¹ Heinrich-Heine-Universität Düsseldorf, Institut für Organische Chemie und Makromolekulare Chemie, Universitätsstraße 1, D-40225 Düsseldorf, Germany.

Abstract

Aroyl-S,N-ketene acetals are obtained by condensation of aroyl chlorides and 2-methyl-N-benzylbenzothiazolium salts in 1,4-dioxane at room temperature in short reaction time in 20-99% yield. This protocol represents a considerable improvement over the standard synthesis in 1,4-dioxane/ethanol mixtures at elevated temperatures.

Keywords: 2-methyl N-benzyl benzothiazolium salts; Einhorn-type acylation; aroyl chlorides; aroyl-S,N-ketene acetals; condensation.