Abstract: A chlorinating agent such as a chloroiminium species is used to remove or neutralize tertiary acetamide present as a contaminant in a tertiary formamide solvent. Tertiary formamide solvent purified or treated in this manner can be used as a reaction vehicle for the chlorination of sucrose-6-acylates, thereby improving the yields of the desired sucralose-6-acylate (an intermediate in the production of sucralose).

Abstract: A method for the preparation of a sucrose-6-ester is disclosed. In a first step of the method, sucrose in a polar aprotic solvent is reacted with an organotin-based acylation promoter. The water of reaction is removed at a temperature that does not exceed about 80° C. In one aspect, the water is removed by distillation of part of the polar aprotic solvent at reduced pressure. In a second step, a carboxylic acid anhydride is added. In one aspect, the resulting reaction mixture is maintained at a temperature of 10° C. or less for a period of time sufficient to produce a sucrose-6-ester. The sucrose-6-ester can be converted to sucralose.

Abstract: A method of removing a carboxylic acid from a liquid including a tertiary amide solvent includes: forming an extraction medium including an acid-extracting tin species and an extraction solvent that is immiscible with the tertiary amide solvent; subsequently contacting the liquid with the extraction medium, forming a phase including a de-acidified tertiary amide solvent and a phase including the extraction solvent; and removing the phase including the extraction solvent, to afford a liquid including the de-acidified tertiary amide solvent. The acid-extracting tin species is one or more tin species obtained by reaction of a di(hydrocarbyl) tin oxide with less than one equivalent of a carboxylic acid, or tin species obtainable by reaction of a 1,3-diacyloxy-1,1,3,3-tetra-(hydrocarbyl)distannoxane with an aqueous base. A method of preparing a sucralose-6-acylate includes uses the foregoing method to remove a carboxylic acid from a liquid including a tertiary amide solvent and the sucralose-6-acylate.

Abstract: A method of removing a carboxylic acid from a liquid that contains a tertiary amide solvent includes a step of contacting the liquid with an extraction medium comprising an amine. The amine is immiscible with both water and the tertiary amide solvent, and the contacting step forms a de-acidified phase containing the tertiary amide solvent and a phase containing the extraction medium and the carboxylic acid. Both the liquid that contains the tertiary amide solvent and the de-acidified phase may also contain a sucrose-6-acylate.

Abstract: The present invention provides a method for producing sucralose from a feed stream resulting from the chlorination of a sucrose-6-acylate in a reaction vehicle. The feed stream includes a sucralose-6-acylate, the reaction vehicle, water, and salts. The salts include one or more selected from the group consisting of alkali metal chlorides, alkaline earth metal chlorides and ammonium chloride. The method includes: (i) deacylation of the sucralose-6-acylate by treatment with a base to afford a product stream comprising sucralose; (ii) partial removal of water and, optionally, reaction vehicle from the product stream of (i) in order to cause precipitation of the salts from the product stream; (iii) removal of the precipitated salts from the product stream of (ii); and (iv) isolation of sucralose from the product stream of (iii).

Abstract: The present invention provides a method for producing sucralose from a feed stream including a sucrose-6-acylate in a reaction vehicle.

Abstract: A method of removing a carboxylic acid from a liquid including a tertiary amide solvent includes: A) forming an extraction medium including an acid-extracting tin species and an extraction solvent that is immiscible with the tertiary amide solvent; B) subsequently contacting the liquid with the extraction medium, forming a phase including a de-acidified tertiary amide solvent and a phase including the extraction solvent; and C) removing the phase including the extraction solvent, to afford a liquid including the de-acidified tertiary amide solvent. The acid-extracting tin species is one or more tin species obtainable by reaction of a di(hydrocarbyl)tin oxide with less than one equivalent of a carboxylic acid, tin species obtainable by reaction of a 1,3-diacyloxy-1,1,3,3-tetra-(hydrocarbyl)distannoxane with an aqueous base.

Abstract: A process for the purification of aqueous feed streams containing sucralose and/or sucralose 6-esters includes, providing an aqueous feed stream including the sucralose and/or sucralose 6-esters, concentrating the aqueous feed stream to form a concentrated aqueous feed stream containing at least 10 wt % total carbohydrates and extracting the concentrated aqueous feed stream with an organic solvent and producing an organic extract and an aqueous extract, in which the organic solvent is immiscible with water, and in which the carbohydrate preferentially passes into the organic extract.

Abstract: A chlorinating agent such as a chloroiminium species is used to remove or neutralize tertiary acetamide present as a contaminant in a tertiary formamide solvent. Tertiary formamide solvent purified or treated in this manner can be used as a reaction vehicle for the chlorination of sucrose-6-acylates, thereby improving the yields of the desired sucralose-6-acylate (an intermediate in the production of sucralose).

Abstract: A method for the preparation of a sucrose-6-ester is disclosed. In a first step of the method, sucrose in a polar aprotic solvent is reacted with an organotin-based acylation promoter. The water of reaction is removed at a temperature that does not exceed about 80° C. In one aspect, the water is removed by distillation of part of the polar aprotic solvent at reduced pressure. In a second step, a carboxylic acid anhydride is added. In one aspect, the resulting reaction mixture is maintained at a temperature of 10° C. or less for a period of time sufficient to produce a sucrose-6-ester. The sucrose-6-ester can be converted to sucralose.

Abstract: A process for the purification of aqueous feed streams containing sucralose comprises: a) extracting an aqueous feed stream comprising sucralose with a first organic solvent and producing a first organic extract and a first aqueous extract, in which the organic solvent is immiscible with water, and a portion of the sucralose passes into the first organic extract; b) optionally extracting the first organic extract with an aqueous solvent to produce a second organic extract and a second aqueous extract, in which the sucralose preferentially passes into the second aqueous extract, and in which the second aqueous extract is recycled to step a); c) concentrating the first aqueous extract to form a concentrated aqueous feed stream; and d) extracting the concentrated aqueous feed stream with a second organic solvent and producing a third organic extract and a third aqueous extract, in which the second organic solvent is immiscible with water, and in which the sucralose preferentially passes into the third organic

Abstract: A process for the recovery of a carbohydrate selected from sucralose and sucralose-6-esters from an aqueous feed stream is disclosed. The process comprises extracting the feed stream with an organic solvent, such as ethyl acetate, back extracting the resulting carbohydrate-containing organic extract with an aqueous solvent, and either crystallizing the carbohydrate from the organic solvent or replacing the organic solvent with water and crystallizing the carbohydrate from water. The process results in an increased overall yield of the carbohydrate.

Abstract: A process for the purification of sucralose in sucralose-containing feed streams is disclosed. The process includes multiple liquid-liquid extraction steps; optionally, a concentration step; multiple crystallization steps; optionally, a chromatography step; and various recycle steps.

Abstract: The present invention provides a method for producing sucralose from a feed stream resulting from the chlorination of a sucrose-6-acylate in a reaction vehicle. The feed stream includes a sucralose-6-acylate, the reaction vehicle, water, and salts. The salts include one or more selected from the group consisting of alkali metal chlorides, alkaline earth metal chlorides and ammonium chloride. The method includes: (i) deacylation of the sucralose-6-acylate by treatment with a base to afford a product stream comprising sucralose; (ii) partial removal of water and, optionally, reaction vehicle from the product stream of (i) in order to cause precipitation of the salts from the product stream; (iii) removal of the precipitated salts from the product stream of (ii); and (iv) isolation of sucralose from the product stream of (iii).

Abstract: A process for the purification of sucralose containing aqueous feed streams is disclosed. The process comprises the step of extracting an aqueous feed stream comprising sucralose and impurities less polar than sucralose, such as tetrachloro saccharides, with an organic solvent that is immiscible with water, such as ethyl acetate. In this step, the mass ratio of organic solvent to aqueous feed stream is in the range of 0.4 to 0.9. Greater than 50% of the sucralose and greater than 95% of the tetrachloro saccharide impurities are extracted into the organic extract. The organic extract is back extracted with water and the resulting aqueous extract recycled to the initial extraction step.

Abstract: A method of removing a carboxylic acid from a liquid that contains a tertiary amide solvent includes a step of contacting the liquid with an extraction medium comprising an amine. The amine is immiscible with both water and the tertiary amide solvent, and the contacting step forms a de-acidified phase containing the tertiary amide solvent and a phase containing the extraction medium and the carboxylic acid. Both the liquid that contains the tertiary amide solvent and the de-acidified phase may also contain a sucrose-6-acylate.

Abstract: The present invention provides a method for producing sucralose from a feed stream including a sucrose-6-acylate in a reaction vehicle.

Abstract: The present invention relates to novel extractive methods for purifying sucralose. The present invention also relates to compositions comprising the sucralose preparations made by the methods of the present invention.