摘要:
Mixtures of isomers, e.g., mixtures of phenethyl bromide and 1-phenyl-1-bromoethane, are separated by (a) selectively condensing one such isomer with an aromatic compound bearing at least one aryl (nuclear) hydrogen atom, e.g., xylene, in the presence of a catalytically effective amount of a Friedel-Crafts catalyst, e.g., ferric chloride, and then (b) separating the product of condensation, e.g., phenylxylylethane, from the unreacted isomer.
摘要:
The invention relates to the preparation of perfluoroalkyl bromides or bromoperfluoroalkanes C.sub.n F.sub.2n+1 -Br (n=1 to 20).A perfluoroalkanesulphonyl chloride C.sub.n F.sub.2n+1 -SO.sub.2 Cl is reacted with a compound of formula: ##STR1## in which X represents a nitrogen or phosphorus atom and R.sup.1, R.sup.2, R.sup.3 and R.sup.4, which may be identical or different, each represent an optionally substituted hydrocarbon radical, it also being possible for one of these symbols to be a hydrogen atom.
摘要:
The invention relates to a process for the preparation of .alpha.,.omega.-bromochloroalkanes. A cyclic ether is hydrobrominated and then the phase obtained is reacted, without any prior purification or separation, with thionyl chloride.
摘要:
A process for the production of hydrogen bromide gas by direct combustion of bromine in hydrogen involves carrying out the combustion reaction in an apparatus chamber made of impregnated graphite and a cooling zone composed of a steel jacket in which are piled blocks of impregnated graphite.
摘要:
A process for the production of hydrogen bromide gas by direct combustion of bromine in hydrogen involves carrying out the combustion reaction in an apparatus chamber made of impregnated graphite and a cooling zone composed of a steel jacket in which are piled blocks of impregnated graphite.
摘要:
A compound (Ia) or (Ib) is prepared by reacting, in a polar aprotic solvent, a compound (III) with a salt of a carboxylic or dicarboxylic acid (IIa) or (IIb). The reaction may be carried out under pressure, but also at normal atmospheric pressure or in the region of normal atmospheric pressure (especially between 0.10 bar and 2 bars). The product (Ia) or (Ib) formed is, in this latter case, recovered continuously as it is formed. ##STR1## R.sup.1, R.sup.2 =optionally substituted saturated or unsaturated acyclic or cyclic hydrocarbon radicals; R.sup.3 =C.sub.1 -C.sub.10 perhaloalkyl; 0
摘要:
A process for the preparation of 3-chloropropionic acid consists especially in simultaneously introducing hydrochloric acid gas and acrylic acid at a molar ratio of 0.7:1 to 1.3:1 into a sediment consisting of 3-chloropropionic acid optionally diluted with water or with an aqueous hydrochloric acid solution.
摘要:
A process for the production of hydrogen bromide gas by direct combustion of bromine in hydrogen involves carrying out the combustion reaction in an apparatus chamber made of impregnated graphite, a chamber outlet composed of a cylindrical segment disposed between a converging segment and a diverging segment, and a cooling zone composed of a steel jacket in which are piled block of impregnated graphite.
摘要:
For the preparation of alkyl halodifluoroacetates, a 1,1-difluorotetrahaloethane is reacted with an alcohol in the presence of air and/or oxygen and a free-radical initiator, such as for example an azo compound, e.g., azobis(isobutyronitrile).
摘要:
The invention relates to the preparation of n-perfluorooctyl bromide. The continuous process according to the invention consists in reacting bromine with 1-hydroheptadecafluoro-n-octane in the gaseous phase, at a temperature between 450.degree. and 520.degree. C. in a Br.sub.2 /C.sub.8 F.sub.17 H mole ratio which can be from 0.2 to 5 and with a contact time between 2 and 240 seconds.The C.sub.8 F.sub.17 Br selectivity is almost complete and information of toxic sub-products like perfluoroisobutene is avoided.