摘要:
A racemic or optically active alkyl 2-chloropropionate is prepared, respectively, from a racemic or optically active alkyl lactate by, in a first step, gradually bringing the alkyl lactate into contact with the thionyl chloride, in the presence of an organic base, while maintaining, in the reaction mixture, an excess of thionyl chloride, relative to the amount of alkyl lactate introduced into this mixture, at a temperature below the decomposition point of the chlorosulphinate of the alkyl lactate, which is formed as an intermediate, and then, in a second step, in heating the reaction mixture resulting from the first step at a temperature which is at least equal to the decomposition point of the chlorosulphinate of the alkyl lactate.The alkyl 2-chloropropionates can be used for the manufacture of the racemic or optically active 2-phenoxypropionic acids.
摘要:
Carbon oxysulfide is obtained in high yield and with high product selectivity and conversion rates by the sulfurization of methanol in the gas phase at elevated temperatures. The starting methanol utilized in the process may be advantageously supplied from natural gas generated at petroleum production sites.
摘要:
Process for the preparation of a compound of general formula (I): in which X represents a halogen atom, by reaction of para-trifluoromethylaniline of formula (II): with a dihalogen X2, the two compounds being introduced simultaneously into a polar aprotic solvent in a dihalogen/compound (II) molar ratio ranging from 1.9 to 2.5 and at a temperature ranging from 100 to 300° C.
摘要:
A method for producing carbon disulfide by sulfurization of sulfur-containing organic compounds is described. Conventional apparatus may be employed with realization of reactant conversion rates approaching 100%, and production of undesirable by-products is insignificant.
摘要:
Process for the preparation of a compound of general formula (I): in which X represents a halogen atom, by reaction of para-trifluoromethylaniline of formula (II): with a dihalogen X2, the two compounds being introduced simultaneously into a polar aprotic solvent in a dihalogen/compound (II) molar ratio ranging from 1.9 to 2.5 and at a temperature ranging from 100 to 300° C.
摘要翻译:制备通式(I)化合物的方法:其中X表示卤素原子,通过式(II)的对三氟甲基苯胺与二卤代X 2 H 2反应,将两种化合物 同时引入极性非质子溶剂中,二卤化物(II)摩尔比为1.9-2.5,温度为100-300℃。
摘要:
Process for the synthesis of methyl mercaptan by the reaction of methanol with hydrogen sulfide wherein a high degree of conversion and enhanced selectivity for the product are obtained by dividing the quantity of catalyst utilized in the reaction into a minimum of three separate portions to form a plurality of reactive catalyst zones and introducing the total amount of hydrogen sulfide reagent into the first of such catalyst zones and thereafter introducing equivalent or alternatively different amounts of the methanol reagent into the consecutive interconnected catalytic zones to react with hydrogen sulfide flowing therethrough while maintaining a molar ratio of hydrogen sulfide to methanol between 1.1 and 2.5. By subdividing the catalyst into separate beds and introducing the reagents consecutively into the catalytic zones, it is possible to maintain the temperature of the reaction mixture within the optimum range and, therefore, to minimize deterioration of the catalyst due to excessive temperature and substantially eliminate the formation of undesired by-products.