Process for the reaction of a low-molecular hydroxyl compound with a carboxylic acid halide
AssigneeHoechst Aktiengesellschaft
InventorKarlheinz Miltenberger
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Abstract
In a process for reacting a low molecular weight hydroxy compound with a carboxylic acid halide, a small amount of the acid halide is introduced into the reaction vessel and the remainder of the acid halide and the hydroxy compound are added gradually in an approximately stoichiometric ratio. The hydrogen halide formed is thus prevented from dissolving in the reaction medium. The heat of reaction to be dissipated is negligible.
Claims8
A process for the preparation of a carboxylic acid or carboxylic acid ester by reacting, in a reaction zone, a hydroxyl compound and a carboxylic acid halide, comprising the steps of:
- introducing into the reaction zone 5 to 20 mol % of the total amount of carboxylic acid halide to be reacted,
- introducing into the reaction zone over a period of time the remainder of said total amount of carboxylic acid halide while introducing into the reaction zone a first amount of hydroxyl compound, said first amount of hydroxyl compound being approximately stoichiometric with respect to said remainder, the rate of introduction of said first amount of hydroxyl compound being approximately stoichiometric with respect to the rate of introduction of said remainder, so that during and at the conclusion of the introduction of said first amount of hydroxyl compound, essentially unreacted carboxylic acid halide is present in the reaction zone,
- adding a second amount of hydroxyl compound which is at least stoichiometric with respect to said essentially unreacted carboxylic acid halide present in the reaction zone at the conclusion of the introduction of said first amount of hydroxyl compound, the total of said first amount and said second amount of hydroxyl compound being 105 to 120 mol %, based on said total amount of carboxylic acid to be reacted.
A process for the preparation of a halogenocarboxylic acid or a halogenocarboxylic acid ester by reacting, in a reaction zone, halogenocarboxylic acid chloride with water or a C.sub.1 -C.sub.12 -alcohol, comprising the steps of:
- first introducing into the reaction zone 5 to 20 mol % of the total amount of halogenocarboxylic acid halide to be reacted,
- then metering into the reaction zone over a period of time the remainder of said total amount of halogenocarboxylic acid halide, while, over essentially the same period of time, metering into the reaction zone a first amount of water or said alcohol, said first amount of water or said alcohol being approximately stoichiometric with respect to said remainder, the rate of metering of said first amount of water or said alcohol being substantially the same, on a molar basis, as the rate of metering of said remainder, so that during and at the conclusion of the metering-in of said first amount of water or said alcohol, at least about 5 mol % of essentially unreacted halogenocarboxylic acid halide, with respect to said total amount of carboxylic acid halide to be reacted, remain in the reaction zone,
- throughout this metering step, removing hydrogen chloride from the reaction zone,
- adding a second amount of water or said alcohol which is in excess over stoichiometry with respect to said essentially unreacted halogenocarboxylic acid halide remaining in the reaction zone, the total of said first amount and said second amount of water or said alcohol being 105 to 120 mol %, based on said total amount of halogenocarboxylic acid, and
- recovering the resulting halogenocarboxylic acid or halogenocarboxylic acid ester from the reaction zone as the product of the process.
Dependencies are inferred from the claim text.