1-(2′,2′,2′-Trifluoroethyl)-4-phosphopyrazoles: Synthese et Etude Spectroscopique ir et RMN 1H, 13C, 19F,et 31P

Seven new 1-fluorinated-4-phosphopyrazoles 2 have been prepared in 60–94% yield by cyclization of N-(2′,2′,2′-trifluoroethyl) phosphonyl β-hydrazones 1 with triethyl orthoformate in the presence of acetic acid. The IR data, the ¹H, ¹³C, ¹⁹F, ³¹P chemical shifts and coupling constants of the compounds 2 are reported.     

The Synthesis of Mono- and Bi-Metallic Platinum(II) and/or (IV) Complexes Containing the Ligand Bis(diphenylphosphino) Methylamine

Complexes of the type [Pt R₂ (dppma-PP′)] (R─Me, Et, Ph, CH₂Ph, C₆H₄ Me-p, C₆H₄OMe-2, CH₂CMe₃, 1-naphthyl, C₆H₄Me-o, dppma = Ph₂PNMe PPh₂) have been prepared from [PtCl₂, (dppma-PP′)] and the corresponding alkyl-lithium or Grignard reagents. Equilibrium constants, k, for the conversion of [PtR₂ (dppma-PP′)] into cis-[PtR₂(dppma-P)₂] with dppma were studied using ³¹P NMR spectroscopy at room temperature. Equilibrium is rapidly established for R─C₆H₄-Me-o, at 20°C. Complex of the type cis-[PtR₂ (dppma-P)₂] was isolated R─C₆H₄ Me-o. The complexes [PtMe₂(dppma-P)₂] and [Pt(o-methoxyphenyl)₂(dppma-P)₂] were prepared, but unfortunately decomposed once isolated, the only evidence for its formation being from ³¹P-{¹H} NMZR spectroscopy. The o-tolyl or 1-naphthyl complexes exist as syn-anti mixtures in solution, due to restricted rotation around the platinum aryl bonds. Treatment of several complexes of the type [PtR₂(dppma-PP′)] with MeI gives [PtR₂Me(I)(dppma-PP′)] with trans addition of MeI. Treatment of [PtR₂(dppma-PP′)] with HCl gives [Pt Cl (R) (dppma-PP′)] for R─C₆H₂Me₃-2,4,6, C₆H₄-CH₃-2, C₆H₄-Me-4, Me, 1-naphthyl. The ¹H, ³¹P NMR parameters for these complexes are discussed. Attempted preparation of complexes of the type [PtR₂ (dppma-P)₂M] (R─C₆H₄-Me-2, Me CN-C₆H₄-Me-4); M─Pd, Pt, Au,) are reported.     

Studies on Quinazolines. Part I. Annelation to the Quinazoline Ring Utilizing Amino Acid Esters

The reaction of quinazoline-4(3H)-thiones 2a-d with amino acid ester hydrochlorides in boiling solvents, under the basic catalysis, afforded the corresponding substitution products (3-6)a-e in low yield. The reaction could be improved by carrying it without a solvent yielding imidazo[1,2-c]- and pyrimido[1,2-c]quinazolines (7-10)a-e . The antibacterial and antifungal activities of the prepared compounds were tested.     

Thio Analogues of Pyrimidine Bases: Syntheses and Spectral Study of New Potentially Biologically Active 2,4-Di-Ortho-(Meta- and Para-)Bromo- (Chloro and Nitro)-Benzylthio-5-Bromouracils (and 6-Methyluracils)

Eighteen new 2,4-di-ortho- (meta- and para-) bromo-(chloro- and nitro-)benzylthio-5-bromouracils (and 6-methyluracils) have been prepared. The structures of these compounds were confirmed by spectral (IR, UV/vis, ¹H NMR) and elemental analyses. Estimation of pharmacotherapeutic potential has been made for synthesized compounds on the basis of prediction of activity spectra for substances (PASS).     

REACTION DES O,O-DIETHYL OXO-1 ALKANEPHOSPHONATES AVEC LES DERIVES DE L'HYDRAZINE: UNE VOIE DE SYNTHESE DES HYDRAZONES α-PHOSPHONATEES ET DES HYDRAZIDES

Abstract

Under the normal conditions, the reaction of hydrazine and methylhydrazine with OO-diethyl 1 oxoalkane phosphonates 1 proceeds by cleavage of the phosphorus-carbon bond and leads to the formation of diethylphosphite 2 and N-acylhydrazide 3 . A procedure has been developed for the synthesis of new primary hydrazone of OO-diethyl 1-oxoalkane phosphonates 4 . A mechanism is proposed. The structure of those compounds 4 was confirmed by NMR and IR spectroscopy.     

Synthesis of some novel 5-substituted benzamido-6-arylamino-pyrazolo[3,4-D]pyrimidin-4-one derivatives for herbicidal activity

Abstract

Sixteen novel 3-methylthio-5-substituted benzamido-6-arylamino-1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4 (5H)-one derivatives (4a–p) were successfully synthesized from iminophosphoranes, aryl isocyanate, and substituted benzoylhydrazine. The structures of the title compounds were elucidated by FT-IR, ¹H NMR, ¹³C NMR, and HRMS. Herbicidal activity of the compounds 4a–p against Brassica napus (rape), Echinochloa crusgalli (barnyard grass), Cucumis sativus (cucumber), and Triticum aestivum (wheat) were determined. The results showed that 5-(2-chlorobenzamido)-6-phenylamino-3-methylthio-1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4 (5H)-one (4c) displayed remarkable inhibition activity against the stalk and root of rape with 100% inhibition rate at the dosages of 10?mg/L and 100?mg/L, and 5-(4-nitrobenzamido)-6-phenylamino-3-methylthio-1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4 (5H) -one (4d) exhibited excellent activity against the stalk and root of barnyard grass with 100% inhibition rate at the same dosages.     

SYNTHESIS,NMR AND MOLECULAR MODELING STUDY OF 4,9a-DIARYL-9,9a-DIHYDRO 1H-[1,4]THIAZINO[4,3-a][1,3]BENZIMIDAZOLES

A series of substituted 4,9a-diaryl-9,9a-dihydro-1H-[1,4]thiazino[4,3-a][1,3]benzimidazoles was prepared in good yields from the reaction of bis(aroylmethyl) sulfides with ortho-phenylenediamine in glacial acetic acid under reflux and under microwave irradiation. Microwave irradiation is found to accelerate the reaction, besides giving better yield in the case of the thiazinobenzimidazoles with electron-withdrawing groups in the aryl rings than the thermal reaction.     

The Efficient Synthesis of 3,4-Dihydropyrimidin-2-(1H)-Ones and Their Sulfur Derivatives with H2SO4 Immobilized on Activated Charcoal

Abstract

Various 3,4-dihydropyrimidin-2-(1H)-ones (DHPMs) and their sulfur derivatives were efficiently synthesized by a one-pot cyclocondensation reaction of aromatic and aliphatic aldehydes, β-dicarbonyl compounds and urea (or thiourea) in the presence of sulfuric acid immobilized on activated charcoal (133% w/w). The reactions were carried out in refluxing n-hexane-acetonitrile (2.5:0.5 mL) within 5–150 min to give 3,4-dihydropyrimidinones (or thiones) in high to excellent yields (81–97%).     

Fluorinated Porous Poly(spirobifluorene) Via Direct C‒H Arylation: Characterization,Porosity, and Gas Uptake

Considering intrinsic properties of conjugated polyfluorenes and special functions of porous polymers, synthesis of fluorinated porous poly(spirobifluorene) via direct C?H arylation polycondensation is explored. Owing to the contorted structure and cross-linking nature, the obtained polymer FPSBF shows permanent porosities with Brunauer–Emmett–Teller specific surface area up to 700 m² g^?1 and exhibits a narrow pore size distribution with the dominant pore size at about 0.63 nm, which is more suitable for adsorption of small gas molecules. Based on the measured gas physisorption isotherms with pressure up to 1.13 bar, the obtained polymer shows good uptaking capacities for hydrogen (1.30 wt% at 1.0 bar and 77 K) and methane (4.80 wt% 1.0 bar and 273 K). Moreover, FPSBF has significant adsorption selectivity for CH₄ against N₂ and the estimated ideal adsorption selectivity ratio is up to 30/1 at 1.0 bar and 273 K, which makes the material possess potential application in gas separation.     

Kinetic Study of Radical Polymerization v. Determination of Reactivity Ratio in Copolymerization of Acrylonitrile and Itaconic Acid by 1H‐NMR

Many reports exist in the literature about the application of ¹H and ¹³C‐NMR techniques to analyze the copolymer structure and composition and also determination of reactivity ratios. In this work, on‐line ¹H‐NMR spectroscopy has been applied to identify reactivity ratios of itaconic acid and acrylonitrile in the solution phase (DMSO as the solvent) and in the presence of AIBN as the radical initiator. All the peaks corresponding to the existing protons were assigned quietly. Therefore, the kinetics of the copolymerization reaction was investigated by studying the variation of integral of two characteristic peaks regarding each monomer. The obtained data were used to find the reactivity ratios of acrylonitrile and itaconic acid by linear least‐squares methods such as Finemann‐Ross, inverted Finemann‐Ross, Mayo‐Lewis, Kelen‐Tudos, extended Kelen‐Tudos and Mao‐Huglin. In addition, a non‐linear least‐square method (Tidwell‐ Mortimer) was used at low conversions. Extended Kelen‐ Tudos and Mao‐Huglin were applied to determine reactivity ratio values at high conversions as well.