Showing papers on "Pyrazoline published in 2001"

The discovery of indoxacarb: oxadiazines as a new class of pyrazoline-type insecticides.

Abstract: The evolution of the insecticidal pyrazoline moiety that was originally discovered in 1972 has led to the discovery of a new crop insecticide, indoxacarb, which is the first commercialized pyrazoline-type sodium-channel blocker. Both monocyclic and fused-tricyclic pyrazolines and pyridazines, as well as structurally related semicarbazones were examined prior to the discovery of analogous tricyclic oxadiazines which had similarly high activity as well as favorable environmental dissipation rates and low toxicity to non-target organisms. The eventual leading candidate, DPX-JW062, was originally obtained as a racemic molecule, but a chiral synthesis was developed which produces material that is 50% ee in the insecticidal (+)-S-enantiomer (DPX-MP062, indoxacarb).

Regioselective synthesis of polysubstituted pyrazoles and isoxazoles.

Abstract: A regioselective synthesis has been developed for the preparation of unsymmetrical 1,3,5-triaryl-4-alkylpyrazolines and -pyrazoles by treatment of α-benzotriazolyl-α,β-unsaturated ketones with monosubstituted hydrazines followed by alkylation at the 4-position of the pyrazoline ring. Reaction of α-benzotriazolyl-α,β-unsaturated ketones with hydroxylamine gives 3,5-disubstituted isoxazoles regioselectively.

Cycloaddition of nitrile imines to resin-bound enamines: a solid phase synthesis of 1,4-diarylpyrazoles

Abstract: The 1,3-dipolar cycloaddition reaction between nitrile imines and resin-bound enamines gives resin-bound pyrazoline intermediates. The piperazine resin functions as a traceless linker and allows these intermediates to be cleaved directly from the resin under mild acid conditions to afford 1,4-diarylpyrazoles. Alternatively they may be chemically modified on the resin prior to elimination from the polymer. The cycloaddition–elimination sequence is regiospecific for the 3,4-disubstituted pyrazole isomer and the products are obtained in good to high yield and in high purity.

6-, 7- AND 8-(5-ARY L-1-PHENYL-2-PYRAZOLIN-3-LY)IMIDAZO- AND PYRIMIDO[2,1-b]BENZOTHIAZOLES AS NOVEL ANTICONVULSANT AGENTS

Abstract: Some new derivatives of 2-amino-5- and 6-(5-aryl-1-phenyl-2-pyrazolin-3-yl)benzothiazole were synthesized from the corresponding aminophenyl compounds by reaction with KSCN/Br2 to build up the benzothiazole ring. The aminophenyl derivatives of pyrazoline were prepared by cyclization with phenylhydrazine of the appropriate 1,3-diphenyl-2-propen-1-one derivatives obtained from arninoacetophenone and differently substituted aldehydes. However, the newly synthesized 2-aminobenzothiazole derivatives of pyrazoline were subjected to cyclization with ethyl brornopyruvate to afford the formation of 6- and 7-(5-aryl-1 -phenyl-2-pyrazolin-3 -yl)-2-ethoxycarbonylimidazo[2,1-b]benzothiazole derivatives. Furthermore, dimethyl acetylenedicarboxylate (DMAD) was used as another cyclizing agent for 2-aminobenzothiazole derivatives to obtain 7- and 8-(5-aryl-1-phenyl-2-pyrazolin-3-y1)-4-methoxycarbonyl-2-oxo-2H-pyrimido[2,1-b]benzothiazole derivatives. The newly prepared compounds were screened for their anticonwlsant activities. However, some of the tested compounds manifested good anticonvulsant potencies.

Coordination Chemistry of a Pyrazoline Derived from 2,4-Pentanedione bis(4-Methylthiosemicarbazone). Crystal Structure of the Pyrazoline and Evidence for Metal-Mediated Ring Opening

Abstract: The heterocyclic structure of the pyrazoline obtained from reaction of 2,4-pentanedione with 4-methyl-3-thiosemicarbazide has been confirmed by X-ray crystallography. Reactions of the pyrazoline with CuII and ZnII have been probed by EPR and NMR spectroscopies respectively. The results suggest that the pyrazoline undergoes ring-opening back to the bis-thiosemicarbazone upon coordination to the transition metal, accompanied by oxidation of the central methylene group when the reactions are carried out under air.

A facile synthesis of 1,3-diphenyl-4-arylspiro[pyrazoline-5, 3′-flavan-4′-one]

Abstract: Synthesis of a series of novel 1,3-diphenyl-4-arylspiro[pyrazoline–5,3′-flavan-4′-ones] has been accomplished in good yields by the regioselective 1,3-dipolar cycloaddition of diphenylnitrilimine with (E) 3-benzylideneflavan-4-ones.

Crystal structure of 1,3,5-triphenyl-2-pyrazoline: a case of spontaneous resolution

Abstract: The crystal structure of 1,3,5-triphenyl-2-pyrazoline has been determined. Although the absolute configuration could not be established, the compound is enantiomerically pure. The 43 structures of pyrazolines, neutral or salts, found in the Cambridge Structural Database have been classified according to their diastereogenic properties.

Synthesis and antimicrobial activity of novel pyrazole, pyrazoline, pyrazolinone and pyrazolidinedione derivatives of benzimidazole.

Abstract: Four novel series of pyrazolylbenzimidazole derivatives have been prepared, namely 2-[(1-substituted phenyl-3,5-dimethyl-4-pyrazolyl)methyl]benzimidazole 5a-d 2-[(1-substituted phenyl-3-methyl-5-oxo-4,5-dihydro-4-pyrazolyl-4-yl)methyl]benzimidazoles 6a-d; 2-[(1-substituted phenyl-3,5-dioxopyrazolidin-4-yl)methyl]benzimidazoles 7a-d and 2-[(4-(1-phenyl-5-aryl-4,5-dihydro-3-pyrazolyl)phenylaminoacetyl]thio- methyl)-benzimidazoles 12a-e. The antimicrobial testing of the prepared compounds was performed using Escherichia Coli (NCTC 5933) as Gram-negative bacteria, Staphylococcus aureus (NCTC 4163) as gram-positive bacteria and Candida albicans (NCTC 5310) as yeast like fungi. The most potent compound was the pyrazolone 6a which exhibits interesting antibacterial activity against the gram-negative bacteria E. coli.

Towards simple and efficient molecular reporters: combining electron transfer and charge transfer in functional dyes of donor–acceptor–spacer–donor constitution

Abstract: Two 1-phenyl-3-R-5-(4-dimethylaminophenyl)-∆ 2 -pyrazolines which are functionalized with the heterocyclic acceptors R = pyridin-2-yl and quinolin-2-yl have been studied as simple and efficient molecular reporters that can be used for multimodal signaling of two different chemical analytes. As revealed by solvatochromic studies including a reference compound (R = 4- chlorophenyl), for derivatives with electron accepting 3-R-substituents in highly polar solvents, the strongly emissive charge-transfer (CT) state of the basic 1-phenyl-3-R-∆ 2 -pyrazoline chromophore is (partly) quenched by a fast intramolecular electron transfer (ET) from the electron-rich but electronically decoupled 5-receptor. In the case of the 3-pyridin-2-yl and 3- quinolin-2-yl derivatives, this donor-acceptor-spacer-donor constitution allows to address the analyte-sensitive CT and ET processes separately by two different chemical stimuli. Metal ion binding to the 3-acceptor position and/or protonation of 3-acceptor and 5-donor lead to various changes of spectral band positions or band intensities, offering a variety of possible detection modes by the choice of absorption, excitation, and emission wavelenghts.

3-pyrazoline-5-one compound and its use

Abstract: PROBLEM TO BE SOLVED: To obtain a new compound which is a specific 3-pyrazoline-5one compound and has excellent control effect of disease injuries on rice blast disease and Helminthosporium leaf spot, etc. SOLUTION: This compound is represented by formula I [R1 to R5 are each H, a halogen, a (substituted)1-3C alkyl or the like; R6 is a (substituted)1-6C or the like; R7 is a (substituted)1-5C alkyl]. The compound of formula I is obtained by reacting a compound of formula II [R11 to R15 are each H, a halogen, a (substituted)1-3C alkyl or the like; R17 is a (substituted)1-5C alkyl] with a compound of the formula R6-X (X is Cl, a 1-3C alkanesulfonyloxy or the like) in an organic solvent in the presence of a base. The compound of formula II is obtained by reacting a compound of formula III with a compound of the formula Z-G (G is trimethylsilyl or the like; Z is a halogen) in an organic solvent in the presence of a base, successively reacting the reaction product with a compound of formula IV and then, reacting the reaction mixture with an acidic water.

Nouvelle méthode de synthèse de quinoxalines associées à différents hétérocycles à cinq chaînons

Abstract: In this paper, we describe the synthesis of new quinoxalines conjugated to different heterocycles that are susceptible to possess various pharmacological and biological activities, utilizing the 1-allyl(propargyl)-3-(ethoxycarbonylmethylene)-2-oxoquinoxaline as starting material.

Binuclear dithiocarbamato complexes of nickel with 1,6-bis(diphenylphosphino)hexane as bridging ligand

Abstract: The new binuclear nickel complexes with 1,6-bis(diphenylphosphino)hexane (dpph = C30H32P2) as bridging ligand of composition [Ni2(μ-dpph)(bz iprdtc)2X2] (X = Cl , Br, NCS; dtc = S2CN ; bz = benzyl C7H7; pr = isopropyl C3H7), [Ni2(μ-dpph) (H-4aapdtc)2X2] (X = Br , NCS, ClO4 ; 4-aap = C11H11N2O; 4-aminoantipyrine = 4-amino-2,3-dimethyl-1-phenyl-3-pyrazoline-5-one = C11H13N3O) and [Ni2(μ-dpph) (plddtc)2X2] (X = Cl , Br, I, NCS; pld = C4H8) have been isolated. These compounds were studied by elemental analyses, IR and UV-VIS spectroscopy, thermal analysis, magnetochemical and conductivity measurements.

Synthesis and Biological Activity of New Selected Different Heterocyclic Nitrogen Compounds Incorporating 1,4‐naphthquinone

Abstract: Condensation of 1-phenylnaphthcyclopentan-2,4,9-trione (II) with aromatic aldehydes yielded the corresponding 3-benzylidene deivatives (III a - f ). Interaction of III a - f with hydrazines, hydroxylamine, urea and thiourea afforded some new (pyrazoline IV a - f , V a - f , Isoxazolino VI a - f pyrimidinone and/or pyrimidinethione, VII a - f , VIII a - f ) derivatives, respectively. Also, a series of some spiro compounds covering β-lactams and thiazolidinones (Xg-j, XIg-j) incorporating 1-phenylnaphthcyclopentan-2,4,9-trione were prepared.

Method for producing N-substituted 2-pyrazoline-5-one

Abstract: not available for EP1230221Abstract of corresponding document: US6515139The present invention relates to a process for preparing N-substituted 2-pyrazolin-5-ones of the formula Iwhere R has the meaning given in claim 1, which comprises reacting a compound of the formula IIwhere R, X and Y have the meanings given in claim 1, at elevated temperature with a molar excess of alkali metal hydroxide in an aqueous reaction medium and then adjusting the pH to pH<=6 by adding an acid.

New pyrazoline derivative, method for producing the same and pest controlling agent

Abstract: PROBLEM TO BE SOLVED: To obtain a new pyrazoline derivative capable of exhibiting excellent pest controlling effects, low toxicity and low residual properties and a pest controlling agent comprising the pyrazoline derivative. SOLUTION: This new pyrazoline derivative is a compound represented by the following formula (I) specifically, e.g. 4-[4-(4-chlorophenoxy) phenylimino]-1,3-dimethyl-2-pyrazolin-5-one).

Some reactions of 3-methyl-5-oxo-1-phenyl-delta 2 -pyrazoline-4-thiocarbohydrazide

Abstract: The reactions of 3-methyl-1-phenyl-5-oxo-Δ 2 -pyrazoline-4-thiocarbohydrazide towards phenyl isothiocyanate, sodium nitrite, cyclohexanone, aromatic aldehydes, and carbon disulphide have been studied. The Vilsmeier-Haack reaction has been applied on 4-substituted pyrazolone derivatives.

Efficient Asymmetric Synthesis of a Functionalized Δ2-Pyrazoline.

Abstract: The first asymmetric synthesis of the (4S,5R)-5-carbomethoxy-4-hydroxy-Δ2-pyrazoline in four steps is described starting from the methyl 4,4-dimethoxy-3-oxobutanoate by sequential catalytic hydrogenation and electrophilic amination.

Pyrazoline derivative or tetrahydropyridazine derivative and medicinal use thereof

Abstract: Using a compound selected from compounds represented by the following formula (1) (which include 3-phenyl-2-pyrazoline derivatives and 3-phenyl-tetrahydropyridazine derivatives) and pharmacologically acceptable salts thereof, an agent is provided which can activate glutamic acid transporter and which is useful for prevention and/treatment of cerebral ischemia (cerebral infarct and brain edema), amyotrophic lateral sclerosis (ALS), etc, all caused by glutamic acid toxicity

The Synthesis of Cross-Linked Poly[styrene(iodoso Diacetate)] and Application in Preparation of Pyrazoline.

Abstract: The 2% cross-linked poly[styrene(iodoso diacetate)] was synthesized, which was applied effectively to the synthesis of pyrazoline derivative, and can be regenerated and reused for the same reaction.