70-34-8

1-Chloro-2,4-dinitrobenzene, 1-fluoro-2,4-dinitrobenzene and 1,3-dinitrobenzene form Meisenheimer complexes with tetra-n-butylammonium fluoride and alumina supported alkali metal fluorides.Both kinetically controlled and thermodynamically controlled complexes are observed.

The halogen exchange reaction of 2,4-dichloronitrobenzene with potassium fluoride in dimethylformamide containing tetrabutylammonium salts has been studied employing an electrochemical detection methodology based upon the use of square wave voltammetry to follow the loss of reactant and the formation of the product and intermediates. The results obtained show that the kinetics of loss of parent material behave on one hand as a dissolution-rate-controlled process and on the other as a homogeneous chemical process. Initially homogeneous reaction dominates the observed kinetics as the presaturated solution is stripped of fluoride ion; at longer time, the observed kinetics are controlled by the rate of KF dissolution. Modeling the system using a fully implicit finite difference method with Richtmyer modification (FIRM algorithm) yielded a mean value for the homogeneous rate constant for the formation of 2,4-dinitrofluorobenzene by reaction of 2,4-dichloronitrobenzene with fluoride ion in DMF at 85 ?°C of 640 ?± 250 mol-1 cm3 s-1 and a mean value for the saturation concentration of fluoride ion of (6.5 ?± 0.5) ?? 10-6 mol cm-3. Ultrasound was found not to significantly enhance the rate of the reaction in the intensity range studied. Furthermore, the utility of microelectrodes for obtaining simple quantifiable voltammetric responses from compounds of which the macroelectrode responses are complicated by chemical followup steps is demonstrated. Ultrasonically induced mixing has been shown to facilitate reproducible microelectrode responses in intrinsically heterogeneous systems.

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The invention relates to the use of a fluorinated gas, wherein the elemental fluorine (F2) is present at a high concentration, the present invention relates to a process for producing fluorinated compounds by direct fluorination using a fluorination gas in which elemental fluorine (F2) is present at a high concentration, such as a concentration of elemental fluorine (F2), in particular equal to much higher than 15 vol% or even 20 vol% (i.e., at least 15 vol% or even 20 vol%), and to a process for producing fluorinated compounds by direct fluorination using a fluorination gas. The process of the present invention relates to the manufacture of fluorinated compounds other than fluorinated benzene by direct fluorination, in particular to the preparation of fluorinated organic compounds, end products and intermediates for use in agricultural, pharmaceutical, electronic, catalyst, solvent and other functional chemical applications. The fluorination process of the invention can be carried outin batches or in a continuous manner. If the process of the invention is carried out in batches, a column (tower) reactor may be used. If the process of the invention is continuous, a microreactor may be used.

We herein present a new family of crown ether-based covalent organic frameworks (CE-COFs) for the first time. The CE-COFs show excellent phase-transfer catalytic performance in various nucleophilic substitution reactions.

A novel silica-KF reagent prepared by hydrolyzing tetraethyl orthosilicate in the presence of KF for fluorination of activated aromatic compounds has been reported. The reagent, as characterized by techniques such as SEM-EDX, XRD and IR spectroscopy, is shown to have potassium cations entrapped inside the silica matrix whereas fluoride anions remain on the surface. Reaction of activated chlorinated aromatic substrates with this silica-KF leads to formation of Meisenheimer complex, either in situ or isolable, finally resulting in regioselective fluorinated aromatics.

Various nitration systems comprising nitric acid, acid anhydride and zeolite H￡] in the absence of solvent are described. Direct double nitration of toluene with a nitric acid, propanoic anhydride and zeolite Hβ system has been developed to give 2,4-dinitrotoluene in 98% yield, with a 2,4-:2,6-dinitrotoluene ratio of 123:1. This system also nitrates activated mono-substituted benzenes (anisole and phenetole) and moderately activated mono-substituted benzenes (ethylbenzene and propylbenzene) to give mainly 2,4-dinitro derivatives. The zeolite can be recovered, regenerated and reused to give almost the same yield as that given when fresh zeolite is used. ARKAT-USA, Inc.

A nitration system comprising nitric acid, propanoic anhydride, and zeolite Hβ has been developed for dinitration of toluene to give 2,4-dinitrotoluene in 98% yield, with a 2,4-:2,6-dinitrotoluene ratio of over 120. This represents the most selective quantitative method for 2,4-dinitration of toluene; the catalyst is reusable, solvent is not needed, and an aqueous work-up is not required.

According to the invention there is provided a method for the nitration of an aromatic compound including the step of reacting the aromatic compound with nitric acid in the presence of an acid anhydride and an aluminosilicate catalyst, in which the acid anhydride is at least one of: ((CnH2n+1)CO)20, where n is 1 to 4 and the moiety CnH2n+1 can be straight or branched chain; ((CHpClq)CO)20, where p is 0 to 2, q is 1 to 3, and p+q = 3; and oxoiane -2, 5-dione, with the proviso that when the acid anhydride is (CH3CO)20, the aromatic compound is toluene, 2-nitrotoluene or 4-nitrotoluene, and the nitration is performed to produce 2,4-dinitrotoluene.

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The present invention relates to boron and aluminum complexes, to the preparation thereof, and to the use thereof for solubilizing ionic compounds. The complexes have one of the following formulae: in which D represents B or Al; R1 represents R, RF, NO2, CN, C(═O)OR, RSO2, or RFSO2; —X1—, —X2—, —X3— and X4 each represent a divalent group >C═O, >C═NC≡N, >C═C(C≡N)2, >CR2R3 or >SO2; —Y1—, —Y2— and —Y3— each represent a divalent group —O—, >N(C≡N), >N(CORF), >N(SO2R4), >NR4, >N(COR4) or >N(SO2RF); R, R2 and R3 each represent H, an alkyl group, an aryl group, an alkylaryl group, an arylalkyl group, an oxaalkyl group or an alkenyl group; R4 represents an alkyl group, an aryl group, an alkylaryl group, a heteroaryl group, an arylalkyl group, an oxaalkyl group, an alkenyl group or an RFCH2— group; RF is a perfluoroalkyl group, a partially fluorinated alkyl group, or a partially or totally fluorinated phenyl group; each of the R′2 and R′3 groups represents R or F.

The reaction of tetrabutylammonium triphenyldifluorosilicate with 2,4-dinitro(trifluoromethoxy)benzene, in acetonitrile and under microwave irradiation, generates a trifluoromethoxide anion which is able to substitute activated bromides (benzyl bromide, cinnamyl bromide), as well as, to some extent, alkyl iodides. Aliphatic trifluoromethyl ethers are thus formed. This is the first example of the nucleophilic displacement of the trifluoromethoxy group from an activated aromatic ring.

A series of dibenzo-18-crown-6 lariat ethers containing two C 7H15 (11), (CH2)2C6F 13 (14), (CH2)2C8F17 (15), NHC7H15 (18) and NHCH2C6F 13 (19) sidearms were prepared and the single crystal X-ray structure of cis-4,4′-di(1H,1H,2H,2H-perfluorodecyl)-dibenzo-18-crown-6 (15a) is reported. The "light fluorous" dibenzo-18-crown-6 ether (14) has emerged as a stable and robust PTC catalyst, which can be recycled efficiently by fluorous solid-phase extraction, and gives better PTC catalytic activity compared to the parent, non-fluorinated PTC catalyst, dibenzo-18-crown-6, and the alkylated derivative (11) in aliphatic and aromatic nucleophilic substitutions.

By reacting calix[4]-1,3-diethoxylaminoethyl derivative (2) with phenyl isothiocyanate, novel dendritic calix[4]-arene derivative (3) with two different branched chains was synthesized in a yield of 78%. By reacting compound 2 with 1,6-diisocyanatohexane or N,N'-bis(2-chloracetamide)ethylene in a ''1 + 1'' intermolecular addition mode, novel lariat calix[4]-1,3-aza-crowns (4 and 5, respectively) with two branched ethoxyl chains were prepared in reasonable yields. The composition, structures, and conformations of all new compounds were confirmed by elemental analyses, IR, ESI-MS, 1H NMR, and so forth. The liquid-liquid extraction experiments showed that all new hosts possessed good extraction abilities towards soft and hard metal cations. The liquid membrane transport experiments suggested that they had good transport abilities for K+ and Ag+. The experiments of phase transfer catalysis indicated that they possessed excellent catalytic properties of aromatic nucleophilic substitution reaction and benzyl nucleophilic substitution. The optimum yields of products in catalytic reaction were as high as approximately 100%.

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Hydrolytically stable and easy to handle trifluoromethyl triflate was found to be a liquid reservoir of 'masked' difluorophosgene. Anhydrous F- sources cleave the S-O bond in trifluoromethyl triflate yielding quantitatively the trifluoromethanolate salts, being useful trifluoromethoxy group carriers. Reaction of trifluoromethanolates with in situ generated from o-trimethylsilylphenyl triflate benzyne leads to (trifluoromethoxy)benzene and fluorobenzene (ratio 85:15). Whereas an addition of trifluoromethanethiolate anion across a triple bond of benzyne leads to [(trifluoromethyl)sulfanyl]benzene solely.

New families of monomeric to dendritic, and monocationic to multicationic (PNP) compounds have been prepared and tested as catalysts in halogen exchange (Halex) reactions. Some of them allow an increase in the efficiency of these reactions which are performed in some cases under the mildest conditions reported up to now.

A new imidazole polymer salt was synthesized in order to develop a high efficiency phase-transfer catalyst for multi-phase reactions. The polymer salt was prepared easily by co-polymerization of 1-1′-(1,4-butamethylene)bis(imidazole) and 1,2-dibromoethane, and has the properties of excellent chemical and thermal stability and high ionic conductivity. It was applied as phase-transfer catalyst in the fluorination of chloronitrobenzenes under the irradiation of microwave and gave excellent yields of corresponding fluoronitrobenzenes. In addition, the enhanced mechanism of microwave was studied and found "non-thermal" effect was a great factor.

A new nucleophilic fluorinating agent, derived from reaction of dimethylaminopyridine (DMAP) with pentafluoropyridine, has been synthesised and assessed in various carbon-fluorine bond forming processes.

A polymerized quaternary ammonium salt polydiallyldimethylammonium chloride, exhibiting high stability to heat and base, was prepared and applied as phase-transfer catalyst (PTC) in halogen-exchange (Halex) fluorination of chloronitrobenzenes to give excellent yields of corresponding fluoronitrobenzenes. Dimethyl sulfoxide was found to be the best solvent when microwave was applied as heating resource.

A novel compound and novel gelatinous substance which have high absorbability, uniform expansion, and elasticity. Although conventional gels include chemical gels and physical gels, no novel gels or compounds have been realized which have fracture resistance, high entropic elasticity, and biodegradability. The present invention provides a novel compound and a novel gelatinous substance which each comprises a crosslinked polyrotaxane obtained by chemically bonding two or more polyrotaxane molecules through the cyclic molecules or rotators thereof.

The nucleophilic aromatic substitution for heteroatom through electrochemical oxidation of the intermediate σ-complexes (Meisenheimer complexes) in simple nitroaromatic compounds is reported for the first time (NASX process). The studies have been carried out with hydride, cyanide, fluoride, methoxy, and ethanethiolate anions and n-butylamine as a nucleophile, at the cyclic voltammetry (CV) and preparative electrolysis level. The cyclic voltammetry experiments allow for detection and characterization of the σ-complexes and they have led us to a proposal for the mechanism of the oxidation step. Furthermore, the power of the CV technique in the analysis of the reaction mixture throughout the whole chemical and electrochemical process is described.

2,2-Difluoro-1,3-dimethylimidazolidine (DFI) is a new deoxo-fluorinating agent that is useful for the conversion of alcohols to monofluorides, and aldehydes/ketones to gem-difluorides under mild conditions.

A preparation process of a fluorine substituted aromatic compound comprising reacting an alkali metal or alkali earth metal salt of an aromatic compound having a hydroxy group with an organic fluorinating agent is disclosed. As a representative fluorinating agent, a bis-dialkylamino-difluoromethane compound, for example, 2,2′-difluoro-1,3-dimethylimidazolidine, is exemplified. According to the process, an industrially useful fluorinated aromatic compound, for example, a fluorobenzene, a fluorine substituted benzophenone, a fluorine substituted diarylsulfone can be prepared with ease in economy without specific equipment.

Disclosed are a fluorinating agent represented by the general formula (1): wherein R1to R4are a substituted or unsubstituted, saturated or unsaturated alkyl group or a substituted or unsubstituted aryl group, and can be the same or different; R1and R2or R3and R4can bond to form a ring including a nitrogen atom or a nitrogen atom and other hetero atoms; or R1and R3can bond to form a ring including a nitrogen atom or a nitrogen atom and other hetero atoms, for example: a preparation process of the fluorinating agent and a process for preparing fluorine compounds by reacting various compounds with the fluorinating agent. The invention has also disclosed that the fluorinating agent is very effective for fluorinating oxygen containing functional compounds.

A convenient and simple regioselective ipso-nitration of arylboronic acids to nitroarenes has been developed. Under certain conditions even dinitro products were isolated.

Using variants of literature methods 2,4- and 2,6- difluorophenyltrimethylsilanes have been bromodesilylated to the corresponding bromodifluorobenzenes in moderate to good yields, 3-bromo-2,6-difluorophenyltrimethylsilane afforded 1,3-dibromo-2,4-difluorobenzene whilst 1,3-difluoro-2,4-bis(trimethylsilyl)benzene yielded 3-bromo-2,6-difluorophenyltrimethylsilane. Application of either the Eaborn or Chvalovsky methods of nitrodesilylation to 4-fluorophenyltrimethylsilane, 2,4-difluorophenyltrimethylsilane and 2,6-difluorophenyltrimethylsilane afforded largely the corresponding desilylated products together with products associated with initial protodesilylation, followed by nitration of the resulting fluorobenzenes. The results obtained show that ipso desilylation in the fluoroaromatic series does follow the expected pattern previously obtained in the hydrocarbon analogues. They also show that in some cases the formation of unusually substituted fluoroarenes can be achieved more readily than by the methods previously used.

A triazolylated tertiary amine compound represented by general formula (I) or a salt thereof, having an aromatase inhibitory activity and being useful for preventing and treating breast cancer, mastopathy, endometriosis, prostatomergaly, etc., wherein A represents a single bond, lower alkylene or carbonyl; B represents lower alkyl, aryl, a 5- or 6-membered heterocyclic group, or a bicyclic fused heterocyclic group; D represents aryl, a 5- or 6-membered heterocyclic group, or a bicyclic fused heterocyclic group; and E represents 4H-1,2,4-triazolyl, 1H-1,2,4-triazolyl or 1H-1,2,3-triazolyl.

Tetramethylammonium chloride (TMAC) is an effective phase transfer catalyst for the selective chloride/fluoride exchange reaction of activated aryl chlorides with potassium fluoride provided that the amount of water in the system is limited and controlled.

Ammonium- and phosphoniumperfluorocyclobutane glides 1 and 2, prepared from perfluorocyclobutene and tertiary amines or phosphines can be used as a masked fluoride anion source. These properties have been demonstrated in several reactions. Ylides 1 and 2 cleave C-Si or O-Si bonds, cause dimerisation of fluoroolefins or react with acid chlorides or activated aromatic compounds under halogen exchange.

A method of inhibiting growth, transformation and/or metastasis of mammalian cells, particularly epithelial cells, in which activity of at least one enzyme, which participates in purine metabolism or regulation of nucleotide levels or the relative ratios of their phosphorylated states, is elevated. In particular, a method of inhibiting transformation, growth and/or metastasis of mammalian cells in which a DNA tumor virus, a DNA tumor virus factor or other factor which has an equivalent effect on cells has acted.

The activity of phase-transfer catalysts during the fluorodechlorination of chloronitroarenes in the absence of aprotic polar solvents was compared.The optimum conditions for the process were selected.

The kinetics of reactions between 1-halogeno-2,4-dinitrobenzene (halogen = F, Cl) and butylamine and piperidine were re-investigated in cyclohexane.The kobs values (s-1 mol-1 dm3) increased with increases in the initial concentration of the reacting amine.Investigation of the reaction mixtures at zero reaction time, indicated the presence of an interaction between the substrate and the amine which occurred in a rapidly established equilibrium and which preceded the substitution process.The nature of the molecular complexes observed is discussed.Present and previous data indicate that the kobs increase was difficult to explain with the traditional hypotesis of proton and leaving group departure as a rate determining step.A better rationalisation of the experimental data may be obtained by involving the molecular complexes on the substitution reaction pathway.

Heteroatomic halides such as 2-chloropyrimidines and 2-chloropyridines, and 2,4-dinitrochlorobenzene underwent halogen-exchange fluorination with the treatment of HF or HF-base solutions to afford the corresponding fluorides in good yields.

Cross-linked styrene/2-(4-chlorophenyl)propene copolymer-grafted tetraphenylphosphonium salt was an effective and reusable catalyst for the reaction of aromatic chlorides with anhydrous potassium fluoride to afford the corresponding aromatic fluorides in good yields.

The compounds of formula I, have been found to have excellent topical activity. They are thus indicated for use in the topical treatment of inflammatory and hyperpoliferative skin diseases and of cutaneous manifestations of immunologically-induced illnesses, such as psoriasis.

Immobilized N-alkylaminopyridinium salts on divinylbenzene crosslinked polystyrene gel was reusable at least 8 times on the reaction of 4-chloronitrobenzene with anhydrous potassium fluoride in tetrahydrothiophene 1,1-dioxide to give 4-fluoronitrobenzene in high yield.The immobilized catalyst was also successfully used for a synthesis of several aryl fluorides in good yields.

In the absence of solvent, either or were found to be effective and practical reagents for the fluorination of several organic halides under mild conditions.

The reactivity of potassium fluoride in nucleophilic fluorine transfer reactions can appreciably enhanced by the presence of tetraphenyl phosphonium bromide.Rate accelerations are especially large in non dipolar aprotic solvents.

Bipyridine complexes of transition metal fluorides which are soluble in aprotic organic sovents are used for the fluorination of organic halides under mild conditons.

Tetraphenylphosphonium hydrogendifluoride acts as a powerful source of F- in various reactions with organic substrates to give fluorine containing products.

Tetraphenylphosphonium hydrogendifluoride, a soluble and thermally stable reagent, acts as a source of fluoride ion in a variety of organic reactions.

The influence of various crown-ethers on the reactions of polychloroaromatic compounds with alkali metal fluorides (KF, RbF, CsF) has been studied.It is shown that the catalytic effect of the crown-ether is almost independent of the nature of the polychloroaromatic substrate and that it is most effective only in a definite range of reaction rates.

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Spray-dried potassium fluoride was found to be much less hygroscopic and much more effective as a fluorinating agent than usual calcine-dried potassium fluoride.Organic compounds containing an activated halogen atom were readily fluorinated in acetonitrile with spray-dried potassium fluoride.

Thieno[1,5]benzodiazepines having useful CNS activity containing the novel tricyclic ring system: STR1 the 10-position being substituted by an amino, preferably a piperazino, group.