Triethanolamine‐catalyzed expeditious and greener synthesis of 2‐amino‐4H‐chromenes

Abstract

Triethanolamine (TEOA), an inexpensive and eco‐friendly base, was used to efficiently catalyze the three‐component condensation reaction of heterocyclic/aromatic aldehyde, (α/β)‐naphthol, and malononitrile in water to give the corresponding substituted 2‐amino‐4H‐chromene derivatives with excellent yields.

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“…A Büchi B-545 instrument was used to measure the melting points. The 1 H NMR (250 or 300 MHz) and 13 C NMR (62.5 or 75) were recorded on a Bruker Avance DPX, FT-NMR spectrometers.…”

“…The reaction of arylaldehydes with malononitrile and 1-naphthol has been utilized for the preparation of 2-amino-4H-chromenes; some acidic and basic catalysts have been applied for this reaction [13][14][15][16][17][18][19][20]. Some biological activities of this class of chromene derivatives include antimicrobial [21], antitumor [22], antiviral [23], and sex pheromone [24] properties.…”

Ethylenediamine Functionalized Cellulose Acetate [CAEDA] Nanosized Solid Base Catalyst in the Synthesis of 2‐Amino‐4H‐Chromenes and 5‐Substituted‐1H‐Tetrazoles

“…substituted 2-amino-4H-chromenes. [39][40][41][42][43][44][45][46][47][48][49][50][51][52] Very recent work has been done to synthesize Alkyl-4-(1H-indol-3 yl)-2-alkyl-4H-chromene-3-carboxylates using water extract of lemon [107] and is still in process but many of the protocols suffer from certain drawbacks such as tedious work-up, long reaction time, harsh reaction conditions etc. So, we present here the synthesis of 2amino-4H-chromenes using dimedone, different substituted aromatic aldehydes and malononitrile using ethanol as a solvent at 80°C in presence of Cellulose acetate [1,2-ethylenediamine][CAEDA] as a catalyst (Scheme 1).…”

“…Much research in context to synthesize this biological moiety viz . substituted 2‐amino‐4 H ‐chromenes [39–52] . Very recent work has been done to synthesize Alkyl‐4‐(1 H ‐indol‐3 yl)‐2‐alkyl‐4 H ‐chromene‐3‐carboxylates using water extract of lemon [107] and is still in process but many of the protocols suffer from certain drawbacks such as tedious work‐up, long reaction time, harsh reaction conditions etc.…”