摘要:
A process for the asymmetric reduction of carboxylic acids of the formula ##STR1## or the amine salts thereof, where R and R.sub.1 are the same or different and are hydrogen, alkyl, cycloalkyl or haloalkyl and Ar is aryl or substituted aryl is disclosed.
摘要:
A process for the asymmetric reduction of carboxylic acids of the formula ##STR1## or the amine salts thereof, where R and R.sub.1 are the same or different and are hydrogen, alkyl, cycloalkyl or haloalkyl and Ar is aryl or substituted aryl is disclosed.
摘要:
A process for the asymmetric reduction of carboxylic acids of the formula ##STR1## or the amine salts thereof, where R and R.sub.1 are the same or different and are hydrogen, alkyl, cycloalkyl or haloalkyl and Ar is aryl or substituted aryl is disclosed.
摘要:
A process for the asymmetric reduction of olefinic amides of the formula ##STR1## where R and R.sub.1 are the same or different and are hydrogen, alkyl, cycloalkyl or haloalkyl and Ar is aryl or substituted aryl is disclosed.
摘要:
A process for the asymmetric reduction of carboxylic acids of the formula ##STR1## or the amine salts thereof, where R and R.sub.1 are the same or different and are hydrogen, alkyl, cycloalkyl or haloalkyl and Ar is aryl or substituted aryl is disclosed.
摘要:
A process for the asymmetric reduction of carboxylic acids of the formula ##STR1## or the amine salts thereof, where R and R.sub.1 are the same or different and are hydrogen, alkyl, cycloalkyl or haloalkyl and Ar is aryl or substituted aryl is disclosed.
摘要:
A process for the asymmetric reduction of carboxylic acids of the formula ##STR1## or the amine salts thereof, where R and R.sub.1 are the same or different and are hydrogen, alkyl, cycloalkyl or haloalkyl and Ar is aryl or substituted aryl is disclosed.
摘要:
A process for the asymmetric reduction of carboxylic acids of the formula ##STR1## or the amine salts thereof, where R and R.sub.1 are the same or different and are hydrogen, alkyl, cycloalkyl or haloalkyl and Ar is aryl or substituted aryl is disclosed.
摘要:
A reaction mixture containing N-hydrocarbylthiophosphoric triamide or N-hydrocarbylphosphoric triamide ("Triamide") is formed by reacting ammonia with N-hydrocarbylaminothiophosphoryl dichloride or N-hydrocarbylaminophosphoryl dichloride in a liquid organic medium, in proportions of at least 16 moles of ammonia per mole of such dichloride and that keep in solution the ammonium chloride co-product formed in the reaction. The temperature of the reaction mixture is kept high enough to keep ammonium chloride-ammonia complex from forming a solid phase in the reaction mixture, but low enough to avoid significant reduction in Triamide yield. The reaction mixture is then caused/allowed to separate into an inorganic phase comprising ammonia, ammonium chloride and co-product thiophosphoric triamide or phosphoric triamide, and an organic phase comprising Triamide, liquid organic medium, dissolved ammonia and, usually, phosphorus impurities. These phases are separated from each other. The ammonia is removed from the organic phase to leave a concentrated solution of Triamide in residual liquid organic medium usually also containing phosphorus impurities. The Triamide is separated or recovered from this residual mixture by continuously introducing a stream of the liquid mixture into a wiped film evaporator operating at a temperature of about 60.degree.-140.degree. C., and at a pressure that avoids solids formation on the heating surface of the wiped film evaporator, and continuously collecting the Triamide product. Triamides are urease inhibitors for use with urea-based fertilizers.
摘要:
Continuously fed to and mixed in a first reactor are (i) a preformed mixture of primary hydrocarbyl monoamine, tertiary amine and liquid inert organic solvent, and (ii) thiophosphoryl chloride while removing heat of reaction to maintain the reaction temperature in the range of about -20.degree. C. to about +50.degree. C. A reaction mixture containing N-hydrocarbylaminothiophosphoryl dichloride is formed. Ammonia and an effluent stream from the first reactor are continuously fed to and mixed in a second reactor in proportions of at least about 16 moles, of ammonia per mole of N-hydrocarbylaminothiophosphoryl dichloride that produce a reaction mixture containing N-hydrocarbylthiophosphoric triamide, and that keep in solution ammonium chloride co-product formed in the reaction. Heat of reaction is removed so that the temperature is high enough to keep ammonium chloride-ammonia complex from forming a solid phase in this reaction mixture, but low enough to avoid significant reduction in yield of N-hydrocarbylthiophosphoric triamide being formed. Effluent is withdrawn from the second reactor so as to maintain a substantially constant volume of reaction mixture in the second reactor. The process eliminates a difficult filtration of the co-product ammonium chloride formed in the second reaction. Also, it possible to accomplish this in a continuous process, with improved efficiency in large scale production of the N-hydrocarbylthiophosphoric triamides. Moreover, the ammonium chloride can be readily converted in the process to an industrially useful liquid co-product mixture.