One‐Pot Synthesis of 2‐Alkyl/Arylamino‐4‐oxo‐4H‐1‐benzopyran‐3‐carboxaldehyde from 4‐Oxo‐4H‐1‐benzopyran‐3‐carboxaldehyde.

Abstract

One-Pot Synthesis of 2-Alkyl/Arylamino-4-oxo-4H-1-benzopyran-3-carboxaldehyde from 4-Oxo-4H-1-benzopyran-3-carboxaldehyde. -A facile one-pot synthesis of the title 2-amino-3-formylchromones (III) (8 examples) via Zn/NH4Cl-mediated reaction of aldehydes (I) with nitro compounds (II) is developed. Surprisingly, 2-arylamino-3-formylchromones cyclize on heating with 70% sulfuric acid furnishing benzopyranoquinolines [cf. (IV)], whereas 2-alkylamino-3-formylchromones produce deformylated products [cf. (V)] under analogous conditions. -(BANDYOPADHYAY*, C.; SUR, K. R.; PATRA, R.; BANERJEE, S.; J. Chem. Res., Synop. 2003, 8, 459-460; Dep. Chem., Miss. Vivekananda Cent. Coll., Rahara 743 186, India; Eng.) -M. Schroeter 11-128

3-(Bromoacetyl)coumarins: unraveling their synthesis, chemistry, and applications

“…These as a versatile scaffold include, for example, alkaline phosphatase, 131 aldose reductase, 110 alpha-glucosidase, 91 and MMP-13 (ref. 40) inhibitors (Fig. 6).…”

“…Several brominating agents have been reported in the last two decades such as tetrabutylammonium tribromide (TBATB), bromine, phenyltrimethylammonium tribromide (PhTAPBr 3 ), N-bromosuccinimide (NBS), and copper(II) bromide (CuBr 2 ) (Scheme 1). [35][36][37][38][39][40][41][42][43][44][45][46][47]…”