| 摘要 |
1,166,143. Carboxylic acids from α-nitroketones. GULF RESEARCH & DEVELOPMENT CO. 13 Feb., 1967 [16 Feb., 1966; 23 Jan., 1967], No. 6720/67. Heading C2C. Carboxylic acids, especially those of formula R 4 COOH are prepared by contacting an organic phase comprising an α-nitro-ketone containing at least four carbon atoms and which has at least one hydrogen atom attached the carbon atom bearing the nitro group, preferably of formula R 4 COCH(R 5 )NO 2 (in which R 4 is a hydrocarbon radical of from 1 to 23 carbon atoms, R 5 is hydrogen or a hydrocarbon radical of from 1 to 23 carbon atoms, the sum of R 4 and R 5 being from 2 to 23) with an aqueous phase containing a catalyst which is a compound that furnishes hydroxyl ions in aqueous solution, the phases being substantially immiscible, and the molar ratio of water in the aqueous phase to the ketone in the organic phase being at least 0À8:1. Specified catalysts include ammonia, amines, and hydroxides, alkoxides, and alkylcarboxylates of alkali and alkaline earth metals, particularly sodium hydroxide. The molar ratio of catalyst to ketone is preferably between 0À1: 1 and 0.01: 1 and the reaction temperature from 20‹ to 150‹ C. The process may also incorporate the additional steps of preparing the α-nitroketone from the appropriate 1-nitro-2-nitroso compound (or its dimer), which in turn can be obtained by nitrosation of a charge stock comprising an α-olefin having from 4-25 carbon atoms. These preliminary processes are the subject of Specification 1,166,142. Examples detail the preparation of heptanoic acid from 1- nitro - octanone - 2, propionic acid from 1- nitro - butanone - 2, and 4 - pentenoic acid from 1-nitro-2-oxo hexene-5. |
