Synthesis of 2-amino-3-cyano-4H-chromen-4-ylphosphonates and 2-amino-4H-chromenes catalyzed by tetramethylguanidine

Synthesis of 2-amino-4H-chromen-4-ylphosphonates and 2-amino-4H-chromenes has been accomplished by the reaction of salicylaldehyde, malononitrile, dialkyl/diphenylphosphites catalyzed by 1,1,3,3-tetramethylguanidine (TMG) under neat conditions at room temperature. The applicability of catalytic TMG for the synthesis of 2-amino-4H-chromenes also has been described. The mild reaction conditions, simple work-up procedure, and use of TMG as an inexpensive catalyst provides an economical protocol for the preparation of important phosphorus-containing compounds.     

Dual basic ionic liquid as a catalyst for synthesis of (2-amino-3-cyano-4H-chromen-4-yl) phosphonic acid diethyl ester and its molecular docking study

Research on Chemical Intermediates - A series of (2-amino-3-cyano-4H-chromen-4-yl) phosphonic acid diethyl ester derivatives were synthesized from salicylaldehyde, malononitrile and...     

One Pot,Multi-component Synthesis of 3-[（4-Aryl-thiazol-2-yl）-hydrazono]-1,3-dihydro-indole-2-one

A series of 3-[（4-phenyl-thiazol-2-yl）-hydrazono]-1,3-dihydro-indole-2-one（4a-4g） and 3-{[4-（2-oxo2H-chromen-3-yl）-thiazol-2-yl]-hydrazono}-1,3-dihydro-indol-2-one（6a-6d） has been prepared in a one-step procedure from condensation reaction of isatin（1）,thiosemicarbazide（2） and bromoacetophenones（3）/or 3-（2-bromoacetyl）coumarins（4）.The method provides a simple and efficient route to prepare the compounds in good yields and in a short experimental time as compared to its stepwise procedure.     

Application of p-TSA in the one pot synthesis of N-methyl-3-nitro-aryl-benzo[4,5]imidazo[1,2-a]pyrimidin-2-amine

A simple, efficient, eco-friendly, and cost-effective method has been developed for the synthesis of N-methyl-3-nitro-aryl-benzo[4,5]imidazo[1,2-a]pyrimidin-2-amine derivatives using 2-aminobenzimidazole, aldehydes and (E)-N-methyl-1-(methylthio)-2-nitroethenamine, in the presence of catalytic amount of p-toluenesulfonic acid (p-TSA) in ethanol at 80?°C conditions. The advantages of this method are the use of an inexpensive and readily available catalyst, shorter reaction times, a wide range of functional group tolerance, and high yield of products via a simple experimental and work-up procedure.     

4-Dimethylaminopyridine-catalyzed multi-component one-pot reactions for the convenient synthesis of spiro[indoline-3,4′-pyrano[2,3-c]pyrazole] derivatives

An efficient and clean reaction process was developed for the convenient and cheap synthesis of spirooxindole derivatives. One-pot reactions of isatins, malononitrile (or ethyl cyanoacetate), hydrazine hydrate (or phenylhydrazine), and 1,3-dicarbonyl compounds were compared with one-pot reactions of isatins, malononitrile (or ethyl cyanoacetate), and 5-pyrazolone derivatives. Both sets of reaction were conducted in EtOH in the presence of 4-DMAP catalyst. A series of spiro[indoline-3,4′-pyrano[2,3-c]pyrazole] derivatives were quickly obtained in excellent yields by using the four-component one-pot reaction method.     

A novel synthesis of diverse 2-amino-5-hydroxy-4H-chromene derivatives with a spirooxindole nucleus by Ca(OH)2-mediated three-component reactions of substituted resorcinols with isatins and malononitrile

An efficient and facile one-pot synthesis is described for the preparation of novel 2-amino-5-hydroxy-4H-chromene derivatives with a spirooxindole nucleus using Ca(OH)₂-mediated three-component reactions of substituted resorcinols with isatins and malononitrile. This simple method provided a variety of biologically interesting diverse 2-amino-5-hydroxy-4H-chromene derivatives in moderate yields under mild reaction conditions.     

A multi-component electro-organic synthesis of 2-amino-4H-chromenes

Electrochemically induced multi-component condensation of resorcinol, malononitrile, and various aldehydes in propanol in an undivided cell in the presence of NaBr as an electrolyte results in the formation of 2-amino-4H-chromenes in good yields and short reaction time.     

An efficient one-pot three-component synthesis of 2-(4-(2-oxo-2H-chromen-3-yl)thiazol-2-yl)-3-arylacrylonitriles and their cytotoxic activity evaluation with molecular docking

A facile, convenient and one-pot three-component method has been outlined for the synthesis of title compounds by treating equimolar amounts of 3-(2-bromoacetyl)-2H-chromen-2-one (2) with 2-cyanothioacetamide (3) and various aryl/heteryl aldehydes (5 or 7) independently. The effect of solvent and catalyst on this one-pot reaction has been studied and the use of l-proline in ethanol was found to be effective to achieve the target compounds (6 & 8) in fair yields. These synthesized compounds were further assessed for the anti-hepatoma activity, and their action mechanism was also investigated by using molecular docking studies. All the compounds 6(a-h) & 8(a-f) manifested excellent potency for anti-hepatoma activity. It should be noted that, compounds 6e, 6f have exhibited almost equipotent activity with reference to standard drug Nexavar.     

Reactions of polyfunctional amines with 3-amino-4-(anilinothio-methylidene)-2-cyano-2-pentenedioic acid diethyl ester

3-Amino-4-(anilinothiomethylidene)-2-cyano-2-pentenedioic acid diethyl ester reacts with ethylenedi-amine, 1,3-propylenediamine and 1,4-butylenediamine affording bicyclic cyclocondensation products. The title compound reacts with diethylenetriamine and 2-(2-aminoethylamino)ethanol to give new seven membered ring tricyclic compounds. The mechanism for these reactions is discussed.     

An unexpected multi-component reaction to synthesis of 3-(5-amino-3-methyl-1H-pyrazol-4-yl)-3-arylpropanoic acids in ionic liquid

A new, one-pot, four-component condensation of 3-methyl-1H-pyrazol-5(4H)-one, ammonium acetate, aromatic aldehydes, and meldrum’s acid in [bmim]BF₄ as solvent is described for the synthesis of 3-(5-amino-3-methyl-1H-pyrazol-4-yl)-3-arylpropanoic acid derivatives. This methodology resulting in excellent isolated yields in short reaction time is characterized by simple work up procedure and little environmental impact.     

An efficient one-pot,multi-component diastereoselective synthesis of functionalized cyclopenta[c]chromenes

A novel one-pot, multi-component diastereoselective synthesis of functionalized cyclopenta[c]chromenes is described. This transformation proceeds via a Michael addition-cyclization reaction sequence between trialkyl phosphites, dialkyl acetylenedicarboxylates and in situ generated 2-(1-(2-oxo-2H-chromen-3-yl)alkylidene)malononitriles from the condensation of 3-acyl-2H-chromen-2-ones and malononitrile.     

Indium(III)chloride catalyzed synthesis of novel 1H-pyrazolo[1,2-b]phthalazine-5,10-diones and 1H-pyrazolo[1,2-a]pyridazine-5,8-diones under solvent-free condition

An efficient, inexpensive and environmentally friendly synthesis of novel 3-amino-2-benzoyl-1-aryl-1H-pyrazolo[1,2-b]phthalazine-5,10-dione and 3-amino-2-benzoyl-1-aryl-1H-pyrazolo[1,2-a]pyridazine-5,8-dione derivatives has been developed via one-pot three-component reaction of phthalhydrazide or maleic hydrazide, aldehydes and arylacetonitrile in the presence of catalytic amount of InCl₃ as a Lewis acid catalyst under solvent-free conditions. The most important features of the present protocol are mild reaction conditions, short reaction times, high yields, and a wide range of functional group tolerance.     

An efficient one-pot synthesis of novel polysubstituted 4-amino-2,3-dihydropyridines

A convenient and efficient one-pot multi-component synthesis of novel polysubstituted 4-amino-2,3-dihydropyridines from carbonyl compounds, malononitrile and acetonitrile, using indium triflate is reported. Acetonitrile acts both as a solvent as well as a substrate.     

A green and convenient approach for the synthesis of methyl 6-amino-5-cyano-4-aryl-2,4-dihydropyrano[2,3-c]pyrazole-3-carboxylates via a one-pot, multi-component reaction in water

A green and efficient one-pot, four-component synthesis of methyl 6-amino-5-cyano-4-aryl-2,4-dihydropyrano[2,3-c]pyrazole-3-carboxylates in water is described. The method is catalyst-free, atom-economical, and does not involve tedious work-up or purification affording the target compounds in good yields.     

One-pot synthesis of 2-amino-4H-chromen-4-yl phosphonate derivatives using β-cyclodextrin as reusable catalyst in water

Various 2-amino-4H-chromen-4-yl phosphonate derivatives were synthesized in good yields by condensation of salicylaldehyde, malononitrile or ethylcyanoacetate, and triethyl phosphite using β-cyclodextrin as a reusable catalyst under neutral conditions, in water.     

Enantioselective organocatalytic synthesis of medicinally privileged 2-amino-4H-chromene-3-carbonitriles via a cascade process

An efficient organocatalytic cascade approach toward medicinally privileged 2-amino-4H-chromene-3-carbonitriles is reported. The enantioselective synthesis of these compounds is achieved in high yields and good to high ee values (up to 96% yield and 89% ee) using bifunctional amine-thiourea organocatalysts developed in our laboratory.     

Organocatalyzed synthesis of 2-amino-8-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carbonitriles

2-Amino-8-oxo-tetrahydro-4H-chromene-3-carbonitriles were synthesized for the first time from a tandem Michael addition-cyclization reaction between cyclohexane-1,2-dione and benzylidenemalononitriles. An enantioselective synthesis of these compounds was achieved in moderate ee values (up to 63% ee) by using a cinchona alkaloid-derived thiourea catalyst.     

New HA 14-1 analogues: synthesis of 2-amino-4-cyano-4H-chromenes

The synthesis of 2-amino-4-cyano-4H-chromene derivatives as new HA 14-1 analogues by a simple and efficient method is reported. In addition, the reaction of 2-amino-2H-chromene-3-carbonitriles, salicylaldehydes and amines results in the formation of new chromeno[2,3-d]pyrimidine derivatives.     

An efficient and simple synthesis of α-amino phosphonates as ‘drug like’ molecules catalyzed by silica-supported perchloric acid (HClO4–SiO2)

An efficient and direct protocol is described for the preparation of α-amino phosphonates derivatives by employing a multi-component, one-pot condensation reaction of aldehyde, amine and trialkyl phosphite in the presence of silica-supported perchloric acid (3 mol%) under solvent-free conditions. The thermal solvent-free green procedure offers advantages such as shorter reaction time, simple work-up, high yield, recovery and reusability of catalyst.     

Phenylboronic acid catalyzed-cyanide promoted, one-pot synthesis of 2-(2-hydroxyphenyl)benzoxazole derivatives

A novel, one-pot, phenylboronic acid catalyzed, cyanide promoted synthesis of 2-(2-hydroxyphenyl)benzoxazoles from salicylaldehydes and o-aminophenols is described. The synthesis is characterized by mild conditions, short reaction times, and simple workup of crystalline, high purity products.