Synthesis of 2‐Amino‐3‐cyano‐4H‐chromene‐4‐carboxamide Derivatives by an Isocyanide‐Based Domino Conjugate Addition/O‐Trapping Rearrangement Sequence

Abstract

An efficient, one‐pot domino synthesis of new 2‐amino‐3‐cyano‐4H‐chromene‐4‐carboxamide derivatives has been developed by the acid‐induced conjugate addition of isocyanides to 2‐imino‐2H‐chromene‐3‐carboxamides, followed by an intramolecular O‐trapping rearrangement, with yields up to 92 %. This newly established protocol was also used in multicomponent (3CR) mode.

Isocyanide-based multicomponent reactions in the synthesis of heterocycles

“…241 It is worth noting that replacing Acid-promoted domino reaction of 2-imino-2H-chromene-3carboxamide derivatives 514 and isocyanides 210 was utilized for the synthesis of novel 2-amino-3-cyano-4H-chromene-4-carboxamides 515 in high yields (Schemes 134 and 135). 242 514 derivatives were obtained via the reaction of salicylaldehydes 516 and cyanoacetamide 517 in the presence of piperidine as catalyst. One pot three-component reaction for the synthesis of 2-amino-3-cyano-4H-chromene-4-carboxamides 515 has also been developed.…”

Isocyanide-based multicomponent reactions for the synthesis of benzopyran derivatives with biological scaffolds

“…Finally, the generated bisiminofuran intermediate 114 underwent further rearrangement and produced the desired product 109 in 30–77% yields. 149…”

“…Finally, the generated bisiminofuran intermediate 114 underwent further rearrangement and produced the desired product 109 in 30-77% yields. 149 In 2013, Soleimani and his group produced 1H-chromeno [2,3-d]pyrimidine-5-carboxamide derivatives 116 through a facile one-pot 3-CR. This approach involves the reaction of isocyanide 3, barbituric acid 115, and salicylaldehyde 2 in the presence of acetic acid in aqueous media.…”

A domino reaction for the synthesis of 2-amino-4 H -chromene derivatives using bovine serum albumin as a catalyst

“…The 2-amino-3-cyano-4H-chromene MX58151 (2) with a *Manuscript Click here to view linked References M a n u s c r i p t 2 3-bromo-4,5-dimethoxyphenyl substituent at the 4-position was considered as a potential agent with multiple action modes against the breast cancer cell line T47D, the lung cancer cell line H1299 and the colorectal cancer cell line DLD-1, and it might have an advantage for the treatment of the drug-resistant cancers as it retains activity in tumor cells resistant towards current antimitotic agents, taxanes (including Taxol and Taxotere), and Vinca alkaloids [3]. Some methods of synthesis of 2-amino-4H-chromenes have already been reported, such as the chemical one pot synthesis of 2-amino-4H-chromenes [5][6][7][8][9], methods resulting in good yields [10][11][12][13] and quite short reaction times [14][15][16][17]. Generally, 2-amino-4H-chromenes are synthesized by multi-component reactions involving in Knoevenagel condensation of salicylic aldehydes with active methylene followed by a intramolecular cyclization step, and have employed organic bases, ionic liquids or organic small molecules as catalysts [10,18,19].…”