Indium bromide catalysed, ultrasound-assisted, regio-selective synthesis of ethyl-5-(trifluoromethyl)-1-(3-substituted-isoquinolin-1-yl)-1H-pyrazole-4-carboxylates

A series of pyrazole-4-carboxylates have been synthesised using indium bromide catalyst and the cyclisation of respective 3-substituted-isoquinolinylhydrazines 1 into their corresponding ethyl-2-(ethoxymethylene)-4,4,4-trifluoro-3-oxobutanoates 3 in ethanol solvent under ultrasonic irradiation at 90?°C for 30 min. The regio-selective cyclisation products were efficiently provided by indium bromide catalyst and are confirmed by nuclear Overhauser effect spectroscopy?Cnuclear magnetic resonance (NOESY?CNMR) studies.     

An Improved and Efficient Preparation of the Chiral NAD(P)H Model (S_s)-1-Benzy1-3-(p-tolylsulfinyl)-1,4-dihydropyridine

Chiral NAD(P)H models are important reduction reagents in asymmetric synthesis. (S,)l-Benzyl-3-(p-tolylsulfinyl)-1,4 1 is one of these models, which canreduce carbonyl and unsaturated compound under mild conditions with highenantioselectivity'. An impressive example is that methyl benzoylformate is reduced byl in the presence of Mg= or Zn' to methyl (R)-mandelate with up to 97% e.e. at roomtemperature'. Our investigation' has shown that the reduction of allylic bromide by Iwithout Mg:* o…     

An Efficient Synthesis of 3-Cyano-1(3H)-Isobehzofuranones

Reaction of o-formyl-N, N-diethylbenzamides (5) with trimethylsilyl cyanide affords the corresponding (0-trimethylsi-lyl)cyanohydrins (6), which on treatment with acetic acid produce 3-cyanophthalides (7) in 80–90% isolated yields.     

An Efficient Route to 2-(Formylmethyl)-Cyclopenten-3-one and Its 1-methyl-Congener

We describe a five-step synthesis of 2-(formylmethyl) - cyclopenten-3-one (1a) and its 1-methyl congener (1b) from 6-methylhept-5-ene-2-one by way of the respective 2-(3-methylbut-2-enyl)-cyclopenten-3-ones (5) and selective ozonolysis of these intermediates.     

Efficient kinetic resolution of racemic 3-nitro-cyclopent(or hex)-2-en-1-yl acetates

The kinetic resolution of 3-nitro-cyclopent(or hex)-2-en-1-yl acetates via enzymatic hydrolysis using Pseudomonas cepacia lipase is described. A model, based on a strong interaction between the nitro group and the active site, accounts for the structural selectivity and the stereoselectivity observed.     

An Efficient One-Pot Synthesis of 3-(2-Benzothiazolyl)coumarins

Some 3-(2-benzothiazolyl)coumarin imines and 3-(2-benzothiazolyl)coumarins are prepared from 2-benzothiazolylacetonitrile and 2-hydroxybenzaldehydes in ethanol in the presence of catalytic amount of NaOH.     

An Improved and Efficient Preparation of the Chiral NAD(P)H Model (SS)-1-Benzyl-3-(p-tolylsulfinyl)-1,4-dihydropyridine

An improved procedure for the preparation of chiral NAD(P)H model, (SS)-1-benzyl-3-(p-tolylsulfinyl)-1,4-dihydropyridine, with satisfactary chemical yield and excellent enantiopurity is reported.     

An efficient procedure for the preparation of (1S,3R)- and (1S,3S)-1-amino-3-(hydroxymethyl)cyclopentanes

Enantiomerically pure (1S,3S)- and (1S,3R)-1-amino-3-(hydroxymethyl)cyclopentanes have been efficiently synthesized from L-aspartic acid. The title compounds are isosteres of ribose and may be used to construct nucleoside analogs with important antiviral and antineoplastic activities as demonstrated by a concise total synthesis of (+)-4'-deoxycarbapentostatin nucleoside.     

Effect of poly(γ‐glutamic acid) on the gelation of Pluronic F127

The gelation of Pluronic F127 aqueous solution was investigated in the presence of sodium poly(γ‐glutamate) (PGA). The gelation temperature was determined based on the tube inversion technique. The gelation temperature increased greatly when the ratio of PGA to F127 was 0.2, and then decreased at higher ratios. The enthalpy of gelation (ΔH_gel) was calculated based on the model of Eldridge and Ferry. A splitting in the model was observed when the PGA/F127 ratio was 0.2 which yielded both a maximum and a minimum of ΔH_gel. These results indicate that PGA can significantly affect the gelation of F127. Copyright © 2008 John Wiley & Sons, Ltd.     

An Efficient and Practical Method for the Synthesis of 1-(2,6-Difluorobenzoyl)-3-(2-alkyl-3-oxopyridazin-4-yl)ureas as Potential Chitin Synthesis Inhibitors

A mild and efficient method for the synthesis of 4-amino-3(2H)-pyridazinones from their corresponding 4,5-dichloropyridazinones under microwave-assisted conditions is described. A series of novel chitin synthesis inhibitors, benzoylphenylureas containing the 3(2H)-pyridazinone, were synthesized. The biological activity of these target compounds was evaluated.     

An Efficient and Practical Method for the Synthesis of 1-(2,6-Difluorobenzoyl)-3-(2-alkyl-3-oxopyridazin-4-yl)ureas as Potential Chitin Synthesis Inhibitors

Summary. A mild and efficient method for the synthesis of 4-amino-3(2H)-pyridazinones from their corresponding 4,5-dichloropyridazinones under microwave-assisted conditions is described. A series of novel chitin synthesis inhibitors, benzoylphenylureas containing the 3(2H)-pyridazinone, were synthesized. The biological activity of these target compounds was evaluated.     

3-(1′-烃氧亚氨基)乙基-4-羟基吡咯啉-2-酮类衍生物的合成与生物活性

以氨基酸乙酯为原料合成8种3-乙酰基-4-羟基吡咯啉-2-酮的类似物A, A与3种烃氧基胺盐酸盐反应合成了20个肟醚类衍生物3-(1'-烃氧亚氨基)乙基-4-羟基吡咯啉-2-酮(B), 其结构经 1H NMR, MS, IR和元素分析表征. 初步生物活性测定结果表明合成的化合物B具有一定的除草活性和抑制真菌活性.     

Synthesis, Crystal Structure and Fungicidal Activity of 3- ( 4- Chloro- 3- ethyl- 1 -methyl- 1 H- pyrazol- 5-yl ) - 6- (E) phenylvinyltriazolo [ 3, 4-b ] - 1,3, 4-thiadiazole

1　ＩＮＴＲＯＤＵＣＴＩＯＮＩｎｒｅｃｅｎｔｙｅａｒｓ ,ｔｒｉａｚｏｌｏ[3,4, ｂ] 1 ,3,4 ｔｈｉａｄｉａｚｏｌｅｄｅｒｉｖａｔｉｖｅｓｈａｖｅｂｅｅｎａｔ ｔｒａｃｔｉｎｇｍｕｃｈａｔｔｅｎｔｉｏｎｆｒｏｍｃｈｅｍｉｓｔｓａｎｄｐｈａｒｍａｃｏｌｏｇｉｓｔｓｂｅｃａｕｓｅｔｈｅｙｓｈｏｗｂｒｏａｄｓｐｅｃｔｒａｏｆｂｉｏｌｏｇｉｃａｌａｃｔｉｖｉｔｉｅｓ,ｓｕｃｈａｓｉｎｓｅｃｔｉｃｉｄａｌ[1 ] ,ａｎｔｉｆｕｎｇａｌ[2 ] ,ｈｅｒｂｉｃｉｄａｌ[3] ,ａｎ ｔｉｂａｃｔｅｒｉａｌ[4] ,ｈｙｐｏｔｅｎｓｉｖ…     

Ethanolic or Aqueous Formic Acid (1:1) - A New Efficient Reagent for the Regeneration of Ketones from Phenylhydrazones

50% Ethanolic or aqueous formic acid has been found to be extremely efficacious for the regeneration of aliphatic and aromatic ketones from phenylhydrazones.     

An Efficient Straightforward Synthesis of (-)-Bulgecinine

(-)-Bulgecinine 1, a component of the antibiotic bulgecins, was efficiently synthesized from (S)-pyroglutaminol2.     

Efficient synthetic methodology for 1-(phenylthio)cyclopropylsilanes,precursors of 1-(lithio)cyclopropylsilanes

Two one flask connective methods for preparing 1-(phenylthio)-cyclopropylsilanes, precursors of 1-(lithio)cyclopropylsilanes, are described.     

An Efficient One-Pot Synthesis of 2,3-Dialkyl-1,1-Diethyl-1-(Acetylamino)-3-(1,1,1-Triphenylphosphanilidene)-1,1,2,3-Propanetetracarboxylates and Their Temperature-Dependent NMR Spectra

Abstract

Stable crystalline phosphorus ylides of 1,1-diethyl 2,3-dimethyl 1-(acetylamino)-3-(1,1,1-triphenylphosphanilidine)-1,1,2,3-propanetetracarboxylates were obtained in excellent yields from the 1:1:1 addition reaction between triphenylphosphine and dialkyl acetylenedicarboxylates in the presence of diethyl acetamidomalonate as a CH-acid. These stable ylides exist in solution as a mixture of two geometrical isomers (E and Z) as a result of restricted rotation around the carbon–carbon partial double bond resulting from conjugation of the ylide moiety with the adjacent carbonyl group on the nuclear magnetic resonance (NMR) time scale at ambient temperature. The dynamic effects in the ylide moieties were investigated by ¹H NMR spectra.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

New Efficient Synthesis of Methyl Trans-2-Aryl (or Hetaryl)-1-Benzamidocyclopropancarboxylates

Methyl trans-2-aryl(or hetaryl)-1-benzamidocyclopropancarboxylates can be easily obtained by thermal decomposition of trans-4-aryl(or hetaryl)-3-benzamido-3-carbomethoxy-Δ¹-pyrazolines synthesized by 1,3-dipolar cycloaddition of diazomethane with methyl E-3-aryl(or hetaryl)-2-benzamido-2-propenoates.