A one-pot four-component synthesis of 3-[(2-amino-4-arylthiazolium-5-yl)(aryl)methyl]-2-oxo-2H-1-benzopyran-4-olates

ABSTRACT

An efficient method has been developed for the synthesis of 3-[(2-amino-4-arylthiazolium-5-yl)(aryl)methyl]-2-oxo-2H-1-benzopyran-4-olates via a tandem reaction involving 4-hydroxycoumarin, benzaldehydes, thiourea, and 2-bromo-1-arylethan-1-ones, using p-toluenesulfonic acid as catalyst in glacial acetic acid under reflux. The identity of the parent product was confirmed by X-ray analyses while the other similar derivatives were identified by NMR. The good yields of the products, regioselectivity, and lack of metal promoters are the main advantages of this protocol.

Highlights

The reaction of 4-hydroxycoumarin, thiourea, benzaldehydes, and 2-bromo-1-arylethan-1-ones leads to the formation of functionalized 3-[(2-amino-4-arylthiazolium-5-yl)(aryl)methyl]-2-oxo-2H-1-benzopyran-4-olates in good yields.

GRAPHICAL ABSTRACT

KEYWORDS:

• 2-Aminothiazole
• 4-hydroxycoumarin
• thiourea
• tandem reaction
• benzaldehydes

Disclosure statement

No potential conflict of interest was reported by the author(s).