Efficient synthesis and characterization of novel bis(chromenes) and bis(benzo[f]chromenes) linked to thiazole units

Abstract

New carbothioamides, linked to chromene or benzo[f]chromene units, were taken as key synthons for the present study. These carbothioamides were prepared, in good yields, by the cyclocondensation of the appropriate 2-hydroxybenzaldehydes or 2-hydroxy-1-naphthaldehyde with 2-cyanoethanethioamide. Next, the precursors carbothioamides were reacted with different α-halocarbonyl compounds and bis(α-bromoketones). These reactions afforded the corresponding 4-(substituted)thiazoles and thiazol-4(5H)-ones, in addition to bis(thiazoles), linked to different cores. Additionally, thiazol-4(5H)-ones were condensed with the appropriate bis(aldehydes) to yield the corresponding bis(thiazol-4(5H)-ones), linked to chromene or benzo[f]chromene units via different cores.

Graphical Abstract

Keywords:

• 3H-Benzo[f]chromen-3-one
• 2H-Chromen-2-one
• hantzsch thiazole synthesis
• thiazol-4(5H)-one

Disclosure statement

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