scholarly journals Green Cyclocondensation of β-Ethylthio-β-indolyl-α, β-unsaturated Ketones with Semicarbazide Hydrochloride as Hydrazine Equivalent in Water: Aqueous Synthesis of 3-Pyrazolyl Indoles

2019 ◽  
Author(s):  
yanhui zhao ◽  
haifeng yu ◽  
peiqiu liao ◽  
wenju wang
Keyword(s):  
Aqueous Synthesis ◽  
Unsaturated Ketones ◽  
Peg 400 ◽  
Cyclocondensation Reaction ◽  
Semicarbazide Hydrochloride

A green and efficient cyclocondensation reaction of β-ethylthio-β-indolyl-α, β-unsaturated ketones with semicarbazide hydrochloride as hydrazine equivalent to prepare 3-pyrazolyl indoles had been developed in the presence of 3 equiv. of PEG-400 in reflux water. This procedure did not require toxic hydrazine and product purification, eliminating the use of toxic liquid chemicals.

Regioselective Synthesis of Isomeric 3-[1-Substituted Pyrazol-3(5)-yl]indoles from β-Ethylthio-β-indolyl-α,β-unsaturated Ketones

Synthesis ◽  
2020 ◽  
Vol 52 (14) ◽  
pp. 2111-2120
Author(s):  
Zemin Mei ◽  
Haifeng Yu ◽  
Peiqiu Liao
Keyword(s):  
Regioselective Synthesis ◽  
Unsaturated Ketones ◽  
Cyclocondensation Reaction

An efficient and highly regioselective synthesis of isomeric 3-[1-substituted pyrazol-3(5)-yl]indoles has been developed by the acid-mediated regioselective cyclocondensation reaction of β-ethyltho-β-indolyl-α,β-unsaturated ketones and monosubstituted hydrazines. In the presence of 1 equivalent of AcOH in refluxing EtOH, the cyclocondensation reaction of β-ethyltho-β- indolyl-α,β-unsaturated ketones with monosubstituted hydrazines yielded 3-(1-substituted pyrazol-5-yl)indoles in excellent yields, while 3-(1-substituted pyrazol-3-yl)indoles were obtained in good yields when the cyclocondensation reaction was carried out in refluxing AcOH.

Bleaching earth clay pH 12.5/PEG-400 catalytic system for synthesis of some novel α, β-unsaturated ketones (chalcones)

2014 ◽  
Vol 41 (7) ◽  
pp. 4673-4678 ◽  
Author(s):  
Milind V. Gaikwad ◽  
Rahul D. Kamble ◽  
Shrikant V. Hese ◽  
Ashok P. Acharya ◽  
Pratima P. Mogle ◽  
...  
Keyword(s):  
Catalytic System ◽  
Bleaching Earth ◽  
Unsaturated Ketones ◽  
Peg 400

Complementary and Regioselective Synthesis of Isomeric 3-[Isoxazol-3(or 5)-yl]indoles from β-Ethylthio-β-indolyl-α,β-unsaturated Ketones

Synthesis ◽  
2021 ◽  
Author(s):  
Haifeng Yu ◽  
Wenju Wang ◽  
Kehua Wang ◽  
Xue Zhang
Keyword(s):  
Efficient Method ◽  
Hydroxylamine Hydrochloride ◽  
Regioselective Synthesis ◽  
Unsaturated Ketones ◽  
Cyclocondensation Reaction

AbstractA simple and efficient method for the complementary and regioselective synthesis of isomeric 3-(isoxazol-5-yl)indoles and 3-(isoxazol-3-yl)indoles has been developed by the regioselective cyclocondensation reaction of β-ethylthio-β-indolyl-α,β-unsaturated ketones and hydroxylamine hydrochloride. It was found that the cyclocondensation reaction in the presence of excess NaOEt in refluxing EtOH gives 3-(isoxazol-5-yl)indoles in good yields, whereas using NaOAc in boiling AcOH gives 3-(isoxazol-3-yl)indoles in good yields.

New Strategy for Synthesis of Anticancer Active Piperastrol, Enastron using Ammonium Sulfocyanate

2020 ◽  
Vol 17 ◽  
Author(s):  
Santoshkumar M. Potdar ◽  
Aishwarya R. Deshmukh ◽  
Krishnakant T. Waghmode
Keyword(s):  
Isopropyl Alcohol ◽  
Inorganic Salt ◽  
One Pot ◽  
Short Reaction Time ◽  
Peg 400 ◽  
Rate Of Reaction ◽  
Cyclocondensation Reaction ◽  
New Strategy ◽  
Biginelli Compounds ◽  
High Yields

Abstract: This report describes an efficient and mild approach for the synthesis of Piperastrol and Enastron via a one-pot three-component cyclocondensation reaction employing ammonium sulfocyanate (NH4SCN) on gram scale in isopropyl alcohol–PEG 400 medium. In this reaction ammonium sulfocyanate is not only one of the reacting components, but also accelerates the rate of reaction to afford Biginelli compounds. High yields, short reaction time and easy workup procedure are the key advantages of the present protocol. Ammonium sulfocyanate is readily available, cheaper, safer and industrial acceptable inorganic salt.

“Green synthesis” of benzothiazepine library of indeno analogues and their in vitro antimicrobial activity

2014 ◽  
Vol 68 (5) ◽  
Author(s):  
Ashok Acharya ◽  
Rahul Kamble ◽  
Snehalkumar Patil ◽  
Shrikant Hese ◽  
Omprakash Yemul ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Acetic Acid ◽  
Ethylene Glycol ◽  
Bleaching Earth ◽  
Poly Ethylene Glycol ◽  
Unsaturated Ketones ◽  
Peg 400 ◽  
Green Route ◽  
Poly Ethylene

AbstractA novel series of indeno-benzothiazepine derivatives was synthesised via a “green” route. Synthesis of these compounds involves the treatment of dinucleophiles such as 2-aminobenzenethiols with α,β-unsaturated ketones in poly(oxyethylene) (poly(ethylene glycol), PEG-400) catalysed by acetic acid. The synthone α,β-unsaturated ketones were obtained by Claisen-Schmidt condensation of indan-1-one with substituted pyrazole-2-carbaldehydes prompted by bleaching earth (pH 12.5) as catalyst and PEG-400 as “green” reaction solvent. Screening of all the synthesised compounds for antimicrobial activity revealed that most of these compounds exhibited moderate to significant antimicrobial activity.

1,4-Reductions of α,β-Unsaturated Ketones and Aldehydes via in situ Generated Hydridocuprates

Synlett ◽  
1989 ◽  
Vol 1989 (01) ◽  
pp. 64-66 ◽  
Author(s):  
Bruce H. Lipshutz ◽  
Christopher S. Ung ◽  
Saumitra Sengupta
Keyword(s):  
Unsaturated Ketones

Enhancement of Solubility and Dissolution Rate of Poorly Water Soluble Drug using Cosolvency and Solid Dispersion Techniques

1970 ◽  
Vol 1 (4) ◽  
pp. 349-356
Author(s):  
Meka Lingam ◽  
Vobalaboina Venkateswarlu
Keyword(s):  
Dissolution Rate ◽  
Solid Dispersions ◽  
Physicochemical Characterization ◽  
Aqueous Solubility ◽  
Water Soluble ◽  
Scanning Calorimetry ◽  
Peg 400 ◽  
Water Soluble Drug ◽  
Poorly Water Soluble ◽  
Poorly Water Soluble Drug

The low aqueous solubility of celecoxib (CB) and thus its low bioavailability is a problem.    Thus, it is suggested to improve the solubility using cosolvency and solid dispersions techniques. Pure CB has solubility of 6.26±0.23µg/ml in water but increased solubility of CB was observed with increasing concentration of cosolvents like PEG 400, ethanol and propylene glycol. Highest solubility (791.06±15.57mg/ml) was observed with cosolvency technique containing the mixture of composition 10:80:10%v/v of water: PEG 400: ethanol. SDs with different polymers like PVP, PEG were prepared and subjected to physicochemical characterization using Fourier-transform infrared (FTIR) spectroscopy, X-ray diffractometry (XRD), differential scanning calorimetry (DSC), solubility and dissolution studies. These studies reveals that CB exists mainly in amorphous form in prepared solid dispersions of PVP, PEG4000 and PEG6000 further it can also be confirmed by solubility and dissolution rate studies. Solid dispersions of PV5 and PV9 have shown highest saturation solubility and dissolution rate

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