Abstract:
The present invention relates to a method for the synthesis of a halogen substituted aryl nitrile, where the halogens are selected from Cl, Br, or I, by reacting an aryl dihalide with a halogen/fluoride exchange reactant to produce a halogen substituted aryl fluoride which is then reacted with a fluoride/cyanide exchange reactant to produce the halogen substituted aryl nitrile.
Abstract:
A process for the hemihydrogenation of aliphatic dinitriles to the corresponding aminonitriles using hydrogen in the presence of a catalyst, a strong inorganic base and water is disclosed. Using the disclosed process, a selectivity for the desired aminonitriles of at least 60% can be achieved.
Abstract:
The present invention concerns a process for the hydroxyalkylation of a carbocyclic aromatic ether. The invention preferably relates to the preparation of 3-methoxy-4-hydroxybenzyl alcohol by the hydroxymethylation of guaiacol. It also concerns the oxidation of the hydroxyalkylated ethers obtained, in particular the oxidation of 3-methoxy-4-hydroxybenzyl alcohol to 3-methoxy-4-hydroxybenzaldehyde, commonly known as "vanillin". The process for the hydroxyalkylation of a carbocyclic aromatic ether of the invention consists of reacting the aromatic ether with a carbonyl compound in the presence of a catalyst and is characterized in that the hydroxyalkylation reaction is carried out in the presence of an effective quantity of a zeolite.
Abstract:
A process for the hydrogenation of halogenonitro-aromatic compounds wherein said compounds are contacted with a nickel-, cobalt- or iron-based catalyst, preferably Raney nickel, and hydrogen in the presence of a sulfur-containing compound. Preferably, the sulfur-containing compound is a sulfoxide or sulfone, and the molar ratio of the sulfur-containing compound to the catalyst ranges from about 1:1 to 10:1.
Abstract:
The invention relates to chemical compounds and their use as catalysts in the solvolysis of alkyl halides. The chemical compounds, when dry, have formula (I):(EO.sub.4 M).multidot.(Imp)p (I)wherein E is selected from the group consisting of phosphorus, arsenic, antimony and bismuth, and is preferably phosphorus, and M is a metal or a mixture of metals.Imp corresponds to a basic impregnating compound consisting of alkaline earth metal, or preferably alkali metal, and their mixtures in combination with a counter-anion to ensure electrical neutrality.The coefficient p is between 10.sup.-2 and 1/3.
Abstract:
The present invention relates to the use as a preserving agent, in particular in cosmetic or dermatological composition, of at least one compound of formula (I): in which:—X represents ═O or —OH;—R1 represents a hydrogen atom or a methyl;—R2 represents a hydrogen atom, a methyl or an ethyl;—R3 represents a C1-C12, saturated or unsaturated, linear hydrocarbon-based radical, optionally substituted with a hydroxyl group (OH); with the exclusion of the compound of formula (I) in which X represents ═O, R1=methyl, R2=H and R3=—(CH2)6—CH3. The invention also relates to certain novel compounds and to the cosmetic or dermatological compositions comprising same.
Abstract:
A fuel feed circuit for an aeroengine, the circuit including a high-pressure pumping system including first and second positive displacement pumps, a hydraulic actuator, and a fuel metering unit. As a function of a position of a slide of the actuator, a feed orifice of the actuator may be connected to a high-pressure delivery orifice connected to an outlet of the second pump, or to a low-pressure delivery orifice connected to a low-pressure feed line. The fuel metering unit includes through sections, one of these through sections being connected to an outlet of the high-pressure pumping system and the other through section being connected to an outlet of the high-pressure pumping system and leading to a high-pressure pilot chamber of the hydraulic actuator.
Abstract:
A fuel-injection device in a turbomachine is disclosed. The device includes a high-pressure pump supplying a flow control valve, whose outlet is connected via a pressurization and cut-off valve to a fuel-injector feed pipe. The valve is connected to the inlet and to the outlet of the pump in order to define two fuel pressurization thresholds, one of which is used to start-up and restart the turbomachine and the other is used for operating the turbomachine from an idle speed and for commanding an equipment with variable geometry.
Abstract:
This invention relates to a control installation (1) of a turbo-machine, comprising: a regulation device (2), a unit (4) located remotely from the device (2) by which it is controlled, a verification system (6) of the unit, comprising: an emitting/receiving antenna (8) connected to the device (2), a passive radiofrequency identification chip (12) mounted on the unit and incorporating information concerning this unit, wherein the chip (12) is designed to emit to the antenna (8) a radiofrequency signal comprising the information, in response to a radiofrequency signal sent by the antenna (8) to verify the unit, The installation is such that the antenna (8) is mounted on the unit (4).
Abstract:
The present invention relates to a process for the acylation of an aromatic thioether. In its preferred variant, the invention resides in a process for the condensation of acetic anhydride or acetyl chloride with thioanisole. The process for the acylation of an aromatic thioether according to the invention is characterised in that it consists in reacting said thioether with an acylating agent chosen from the group formed by the halides of carboxylic acids and the anhydrides of carboxylic acids, in the presence of an effective quantity of an acid zeolite.