Pot, atom and step economic (PASE) synthesis of 5-isoxazolyl-5H-chromeno[2,3-b]pyridine scaffold

PASE Pseudo-Four-Component Synthesis and Docking Studies of New 5-C-Substituted 2,4-Diamino-5H-Chromeno[2,3-b]pyridine-3-Carbonitriles

“…Initially, we tested the one‐pot, pseudo‐four component reaction between salicylaldehyde 1 a , malononitrile 2 and dimedone 3 a (Table ). Refluxing of starting compounds in pyridine (Entry 1, this conditions are optimal for our previous chromeno[2,3‐ b ]pyridine PASE synthesis from salicylaldehydes, 2‐aminoprop‐1‐ene‐1,1,3‐tricarbonitrile and 3‐arylisoxazol‐5(4 H )‐ones) gave only 42 % yield of 2,4‐diamino‐5‐(2‐hydroxy‐4,4‐dimethyl‐6‐oxocyclohex‐1‐en‐1‐yl)‐5 H ‐chromeno[2,3‐ b ]pyridine‐3‐carbonitrile 4 a . 1‐Propanol and ethanol were also examined as a solvents.…”

“…Although these processes provide with a wide variation of aryl substituents at the 5‐position of the 2‐amino‐3‐cyanochromeno[2,3‐ b ]pyridine scaffold, this one‐pot reaction does not proceed with hydroxyaromatics bearing electron‐withdrawing groups, e. g., halogens, which considerably limits the scope of accessible structures. (2) from salicylaldehydes, malononitrile (or its dimer) and S‐, N‐ or C‐ source (Scheme ). In comparison with first case in the second one the chromeno[2,3‐ b ]pyridine core is composed from two starting molecules exclusively.…”

“…This approach makes it possible to obtain 5‐S, 5‐N and 5‐C substituted chromeno[2,3‐ b ]pyridines. For a present moment only one synthesis of chromeno[2,3‐ b ]pyridine with “5 C−C” configuration has been reviewed according Scheme …”

Pot‐, Atom‐ and Step‐Economic (PASE) Multicomponent Approach to the 5‐(Dialkylphosphonate)‐Substituted 2,4‐Diamino‐5H‐chromeno[2,3‐b]pyridine Scaffold

“…In the last few years we also realized multicomponent transformations of salicylaldehydes, 2‐aminoprop‐1‐ene‐1,1,3‐tricarbonitrile (malononitrile dimer) and 3‐phenylisoxazol‐5(4 H )‐one, or 1,3‐cyclohexanediones into 2,4‐diamino‐5‐(5‐oxo‐3‐phenyl‐2,5‐dihydroisoxazol‐4‐yl)‐ or 2,4‐diamino‐5‐(2‐hydroxy‐6‐oxocyclohex‐1‐en‐1‐yl)‐5 H ‐chromeno[2,3‐ b ]pyridine‐3‐carbonitriles.…”

Design and synthesis of benzothiazole/thiophene-4H-chromene hybrids

“…Our research group is actively engaged in developing multicomponent reaction protocols for accessing diverse scaffolds particularly 4-heterocycle-substituted-4H-chromene with inherent exibility for incorporating appendages including replacing the benzene ring of chromene moiety by heterocyclic ring, by innovative design and synthesis of building blocks. [28][29][30][31][32][33][34] Herein we disclose the design ( Fig. 1) and synthesis of hybrid heterocyclic's by simultaneous incorporation of substituent's at 3 and 4 positions of 4H-chromenes in an efficient three component reaction (Fig.…”