The Synthesis and Chemistry of 2-Imino-2H-Chromene-3-Carbo(Thio) Amides

2-Imino-2H-chromene-3-carbo(thio)amides are considered versatile compounds because of their significance as building blocks in synthetic chemistry. In this review, we display all the available synthetic methods for 2-imino-2H-chromene-3-carbo(thio)amides as well as their reactions towards the different reagents. The presence of the imino and amide groups in these compounds makes C-4 the only reactive site of the pyran ring with a unique reactivity that could react with different reagents. The appropriate applications for the synthesis of condensed chromene derivatives and their relevancy are reported. The reactions of 2-imino-2H-chromene-3- carbo(thio)amides were divided into several categories depending on the used reagents in the reactions.