PEG-400 remarkably efficient and recyclable media for one-pot synthesis of various 2-amino-4H-chromenes

Abstract

Polyethylene glycol-400 has been found to be a recyclable and rapid reaction medium for the synthesis of 2-amino-4H-chromenes by the condensation of aromatic aldehyde, malononitrile, and a-naphthol. This method gives remarkable advantages such as simple work up, high yields, and a greener method by avoiding toxic catalyst and hazardous solvents.

Cysteic acid grafted to magnetic graphene oxide as a promising recoverable solid acid catalyst for the synthesis of diverse 4H-chromene

“…Because of the benefits of MCRs and the great importance of 4 H -chromenes, syntheses of these compounds have been developed using different catalysts in the multicomponent reaction between malononitrile (or ethyl cyanoacetate), a diverse electron-rich phenol or enolizable carbonyl compound, and an aldehyde 1 . Recent catalytic systems for the synthesis of 4 H -chromene derivatives consist of Fe(HSO 4 ) 3 28 , nickel nanoparticles 29 , ZrO 2 nanoparticles 30 , Zn 4 O(H 2 N-TA) 3 31 , ZnS nanoparticles 32 , nano-sized MgO 33 , CoFe 2 O 4 34 , CuO-CeO 2 35 , egg shell 36 , chitosan 37 , polymer-supported palladacycles 38 , [2-aemim][PF 6 ] 39 and TMG-[bmim][X] 40 under microwave radiation, [bmim]OH 41 , IL-HSO 4 @SBA-15 42 , hexadecyltrimethylammonium bromide 43 , l -proline 44 , l -proline-melamine 45 , tetraalkylammonium halides 46 – 49 , SB-DBU.Cl 50 , potassiumphthalimide- N -oxyl 51 , potassium phthalimide 52 , sodium selenate 53 , sodium alginate 54 , Sodium ethylene diamine tetraacetate 55 , morpholine 56 , 4-dimethylamino- pyridine 57 , 4-DMAP 58 , piperidine 18 , 59 , piperidinium acetate 60 , (DHQD) 2 PYR 61 , tungstic acid functionalized mesoporous SBA-15 62 , 1,8-diazabicyclo[5.4.0]undec-7-ene 63 , glycine 64 , imidazole 65 , heteropolyacid 66 , meglumine 67 , Mg/Al hydrotalcite 68 , PEI@Si–MNP 69 , PEG-SO 3 H 70 , alumina 71 , nano-sized zeolite clinoptilolite 72 , Nickel Nanoparticles …”

A Green Method Synthesis and Antimicrobial Activity of 2-Amino-4H-Chromene Derivatives

“…This type of reaction was highly important in medicinal chemistry because it allows highly complex poly functional molecule through one-pot simple and one step reaction [16]. Multicomponent reactions with environmentally benign solvents and catalytic synthesis are one of the suitable green protocols, which meet the requirements of green aspects of developing library of biomolecules by organic synthesis [17]. Organic reaction carried out in water has become highly popular in recent trends due to its specific medicating organic reactions and it's environmentally friendly [18].…”

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

“…Moreover, other catalysts such as methanesulfonic acid, imidazole, porous organic polymers (POPs), potassium phthalimide, l ‐proline‐melamine, sodium malonate, and Na 2 CO 3 have also been utilized for this transformation. In recent years, several new green methods have been reported using cetyltrimethylammonium chloride, KF/Al 2 O 3, basic γ–alumina, MgO, CuSO 4 ·5H 2 O, DBU, CTABr/ultrasound irradiation, nanocatalyst, bael fruit extract (BFE), water extract of lemon fruit shell ash (WELFSA), and poly(ethylene glycol) (PEG) in water . Although various procedures for the synthesis of 2‐amino‐4 H ‐chromenes are known, many of these methods have disadvantages such as expensive and unique catalysts, long reaction times, utilization of microwave or ultrasonic irradiation, and affording only moderate yields .…”