A convenient synthesis of 2-acyl benzothiazoles/thiazoles from benzothiazole/thiazole and N, N'-carbonyldiimidazole activated carboxylic acids. Issue 25 (20th June 2019)

• Record Type: Journal Article
• Authors: Huang, Tonghui; Wu, Xin; Yu, Yongbo; An, Lin; Yin, Xiaoxing
• Is Part Of: Tetrahedron letters. Volume 60:Issue 25(2019)
• Page Start: 1667
• Page End: 1670
• Publication Date: 2019-06-20
• Subjects: 2-Acyl thiazoles -- 2-Acyl benzothiazoles -- Grignard reagents -- Acylation; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tetlet.2019.05.043
• Languages: English
• ISSNs: 0040-4039

Abstract

Graphical abstract: Conditions: (a) i -PrMgCl·LiCl, THF, −10 °C, 30 min. (b) N, N'-carbonyldiimidazole, THF, r.t., 1 h. (c) THF, −10 °C to r.t., 3 h. Highlights: Synthesis of 2-acyl benzothiazoles/thiazoles from various carboxylic acids. Appropriate for Boc-protected amino acids and dipeptide. Moderate to excellent yields under mild reaction conditions. Abstract: A convenient and efficient strategy for the synthesis of 2-acyl benzothiazoles/thiazoles has been developed. The treatment of benzothiazole/thiazole with allylic Grignard reagents readily generates the corresponding 2-Grignard reagents, which is followed by a reaction with N, N'-carbonyldiimidazole activated carboxylic acids to afford various 2-acyl benzothiazoles/thiazoles products. The synthetic method is applicable to a wide array of carboxylic acids and allows easy access to 2-acyl benzothiazoles/thiazoles with considerable yields under mild reaction conditions.