Efficient Synthesis of (3E)‐3‐[Amino(aryl)methylidene]chromane‐2,4‐diones (=(3E)‐3‐[Amino(aryl)methylene]‐2H‐1‐benzopyran‐2,4(3H)‐diones) via a Three‐Component Reaction

Abstract

The Michael‐type addition of a 4‐hydroxycoumarin (=4‐hydroxy‐2H‐1‐benzopyran‐2‐one) 1 to a β‐nitrostyrene (=(2‐nitroethenyl)benzene) 2 in the presence of AcONH4 leads to substituted (3E)‐3‐[amino(aryl)methylidene]chroman‐2,4‐diones (=(3E)‐3‐[amino(aryl)methylene]‐2H‐1‐benzopyran‐2,4(3H)‐diones) 4 (Table 1). High yields, short reaction time, and easy workup are advantages of this novel one‐pot three‐component reaction.

Nitroalkane‐Mediated Multicomponent Synthesis of β‐Enaminones

“…Among various reported MCRs, the one‐pot coupling of 1,3‐diketone, aldehyde, and amine in different solvents that gives a pseudo four component product (Scheme ) has been considered to be one of the most frequently employed MCRs . Nevertheless, when aldehyde is replaced by the corresponding nitrostyrene, the major product for this MCR was found to be the β‐enaminones ,. To the best of our knowledge, no effort has been made to synthesize β‐enaminones from commercially available 1,3‐diketone, aldehyde, and amine.…”

PEG Mediated Eco-Friendly One Pot Sunthesis of Benzylamine Coumarin Derivatives Using Multicomponent Reactant

“…The vast biological significance of the amino derivatives of 4-hydroxycoumarin inspired us to develop a novel protocol for the efficient synthesis of new benzylamine coumarin derivatives. A number of synthetic protocols have been applied for the synthesis of nitrogen containing coumarin derivatives [12][13][14][15]. Mannich reaction [16] is the best method to synthesize such type of compounds.…”

“…Mannich reaction [16] is the best method to synthesize such type of compounds. The methods reported previously for the synthesis of benzylamine coumarin derivatives suffer from severe disadvantages such as longer reaction time, inadequate yields and use of expensive catalyt [13,14]. Thus, the development of environmentally benign, high-yielding, and fast synthesis of benzylamine coumarin derivatives still remains a desired goal in organic synthesis.…”

One-Pot Stepwise Approach to β-Enaminoketoesters through “Masked” 1,3-Aza-Dipoles

“…β-Enaminoketoester, a versatile building block to construct a variety of molecules, has been used to react with hydrazine to afford pyrazole and also to synthesize chiral β-amino acid by asymmetric hydrogenation . Tandem Blaise-acylation is known to proceed to β-enaminoketoesters via Reformatsky reaction with nitrile; 1,3-ketoester condensation with Me 2 NCH(OMe) 2 also affords the desired product . Herein we are interested in discovering a two-step, one-pot protocol to synthesize β-enaminoketoesters via “masked” 1,3-aza-dipoles.…”