The Eschenmoser's Salt as a Formylation Agent for the Synthesis of Indolizinecarbaldehydes and Their Use for Colorimetric Nitrite Detection

C−H bond formylation is the most immediate way to incorporate versatile formyl group into (hetero)aromatics. However, type of reagents and severe conditions involved in classical methods often curtail their application, especially presence other functional groups. Herein, we present Eschenmoser's salt, a commercially available (dimethylamino)methylating chemical, as useful reagent for indolizines compounds. The method straightforward mild, furnishing indolizinecarbaldehydes modest-to-good yields with exclusive remote regioselectivity. Furthermore, these compounds can be easily transformed push-pull dyes are highly selective colorimetric detection nitrite, substance extensively employed preservative food industry, concentration which crucial control prevent harmful effects living organisms. assay simple, allowing naked-eye nitrite solution or on cotton swab wide range concentrations.