Abstract:
The present invention relates to a process for the preparation of β- or γ-unsaturated or saturated carboxylic acids.It relates more particularly to the hydroxycarbonylation of an organic compound comprising a conjugated unsaturation, such as butadiene, by the action of carbon monoxide and water in the presence of a palladium-based catalyst. The carboxylic acids thus obtained are preferably pentenoic acids. According to the invention, the reaction medium after the end of the hydroxycarbonylation stage is treated with hydrogen to reduce the palladium present in the 2+ oxidation state to palladium in the zero oxidation state and the precipitated palladium is recovered.
Abstract:
Dinitro aromatic compounds are improvedly prepared by reacting an aromatic compound with a nitric acid nitrating agent and thence separating the nitrating acid from the process stream thus formed, the process stream containing said at least one dinitro aromatic compound and also having a fraction of the nitrating acid dissolved therein, the subject process also comprising (a) distilling/stripping nitric acid from said process stream, (b) recovering nitric acid from the top of the distillation/stripping vessel and recycling same to the nitration reaction and (c) washing the process stream which contains the at least one dinitro aromatic compound, but having the nitric acid removed therefrom.
Abstract:
The present invention concerns a process for the preparation of a 4-hydroxybenzaldehyde and its derivatives. More particularly, the invention concerns the preparation of 3-methoxy-4-hydroxybenzaldehyde and 3-ethoxy-4-hydroxybenzaldehyde, respectively known as vanillin and ethylvanillin. The process for the preparation of a 4-hydroxybenzaldehyde and its derivatives is characterized in that it consists of selectively oxidising, to a carboxy group, the group in the 2 position with respect to the hydroxyl group, present in the phenolic compounds in a mixture comprising at least a phenolic compound (A) carrying formyl and/or hydroxymethyl groups in the 2 and 4 position, a phenolic compound (B) carrying a formyl or hydroxymethyl group in the 4 position, a phenolic compound (C) carrying a formyl or hydroxymethyl group in the 2 position, resulting in a mixture comprising a 3-carboxy-4-hydroxybenzaldehyde, a 4-hydroxybenzaldehyde and a 2-hydroxybenzoic acid, which then undergoes a decarboxylation operation to produce the 4-hydroxybenzaldehyde and a phenol which can optionally be recycled.
Abstract:
The present invention concerns a process for the preparation of 3-carboxy-4-hydroxybenzaldehydes and derivatives thereof from phenolic compounds carrying formyl and/or hydroxymethyl groups in the 2 and 4 positions. The invention also concerns the preparation of 4-hydroxybenzaldehydes from 3-carboxy-4-hydroxybenzaldehydes. More particularly, the invention concerns the preparation of 3-methoxy-4-hydroxybenzaldehyde and 3-ethoxy-4-hydroxybenzaldehyde, respectively known as "vanillin" and "ethylvanillin". The process for the preparation of 3-carboxy-4-hydroxybenzaldehyde is characterized in that the group in the 2 position in a phenolic compound carrying formyl and/or hydroxymethyl groups in the 2 and 4 positions is selectively oxidized to a carboxy group, and optionally a hydroxymethyl group in the 4 position is selectively oxidized to a formyl group. A successive decarboxylation step for a 3-carboxy-4-hydroxybenzaldehyde produces a 4-hydroxybenzaldehyde.
Abstract:
The present invention relates to novel cyclic sulphates of (poly)glycerol, particularly to the novel compound of 4-(hydroxymethyl)-1,3,2-dioxathiolane-2,2-dioxide. The present invention also relates to the preparation process of the cyclic sulphate compounds, and to the use thereof as an intermediate to prepare green surfactants containing sulphate groups.
Abstract:
The present invention relates to methods of improving germination rates of plants or crops, and of preventing or arresting water evaporation loss from targeted soil areas by use of soil additives, which allow for improved water utilization by crops, plants, grasses, vegetation, etc.
Abstract:
Disclosed is a process to produce a hypophosphite salt defined as [C+ hypophosphite−] by reacting P4 with a hydroxide salt defined as [C+OH−], or a hydroxide salt precursor and a catalyst, wherein C+ is the cationic moiety of [C+ hypophosphite−] salt.
Abstract:
The invention relates to a system implements a mobile phone (20) available to a user (18) authorized to open a lock (22). A remote management site (10) includes a database (12) of locks and authorized users identified by the mobile phone number thereof, as well as a generator (14) of accreditation data. The accreditations are encrypted acoustic accreditations in the form of single-use audio signals, capable of enabling the opening of locks that are indexed in the database. The system includes means for securely transmitting the encrypted acoustic accreditations from the management site to the mobile phone of the corresponding authorized user via a mobile network operator (16). The lock (22) includes an electroacoustic transducer that is capable of sensing the acoustic accreditations reproduced by the telephone placed beforehand near the lock, as well as a means for recognizing, analyzing, and authenticating the sensed acoustic accreditations, and controlling the unlocking of the mechanical members upon recognizing a compliant accreditation.
Abstract:
The invention relates to novel dendritic polymers having biphosphonic terminations, to derivatives thereof, to a method for preparing them and to their uses.
Abstract:
Environmentally-polluting nitrocresol values are removed from admixtures of nitroaromatic compounds comprised thereof, notably the media of nitration of aromatic compounds by reacting same with aqueous HNO.sub.3 /H.sub.2 SO.sub.4, by first intimately contacting such nitroaromatic compound admixtures with an oxidizing agent comprising hydrogen peroxide, javelle water, or mixture thereof, and thereafter with a neutralizing agent; the nitroaromatic aromatic compounds thus purified are conveniently catalytically hydrogenated into aromatic amines.
Abstract translation:通过首先使这种硝基芳族化合物外加剂与包含过氧化氢,悬浮液的氧化剂紧密接触,从而与其组成的硝基芳族化合物的混合物,特别是芳族化合物硝化的介质从HNO 3 / H 2 SO 4水溶液中除去环境污染的硝基甲酚值 ,或其混合物,然后用中和剂; 如此纯化的硝基芳族芳族化合物方便地催化氢化成芳族胺。