An efficient, expedient, clean and environmental being synthesis of tetrahydrobenzo[b]pyran's twenty derivatives (4 a–t) has been reported via one‐pot three component condensation reaction of various benzaldehydes, dimedone and malononitrile in presence of ionic liquid [(EMIM)Ac] as a catalyst at ambient temperature in ethanol. Advantages of these reaction follow the principle of green chemistry, which are operational simplicity, shorter reaction time, and mild reaction conditions with high yield (78–98 %) products.

An efficient, and simple protocol for the synthesis of extremely functionalized pyrano[3,2‐c]chromen‐5‐ones (4 a–v) has been developed. One‐pot multicomponent cyclo‐condensation of 4‐hydroxycoumarin, aromatic‐aldehydes, and (E)‐N‐methyl‐1‐(methylthio)‐2‐nitroethenamine (NMSM) catalyzed by ionic liquid [(EMIM)Ac] in two different methods as methanolic mediated and at solvent free condition is described which presumably involve the Knoevenagel reaction succeeding Michael‐addition and O‐cyclization with elimination of methanethiol. The noteworthy features of this protocol are use of ionic liquid as catalyst, good to excellent yield, optimum reaction time with easy experimental procedure. The prepared derivatives were characterized by IR, 1HNMR,13CNMR and HRMS spectroscopic techniques.

been developed because of these motifs' advanced applicability, which prompted researchers to study this molecule. We focused on this synthesis advancement till the last quarter of the year 2022 which summarizes all results of MCRs obtained in conventional and non-conventional media. It will serve as a key role for synthetic organic chemists working in this field.

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