Purification of tertiary formamide contaminated with tertiary acetamide

摘要

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).

主权项

1. A process comprising:
a) recovering a crude recycle solvent stream comprising a tertiary formamide and a tertiary acetamide from a mixture comprising at least one substance less volatile than the tertiary formamide and the tertiary acetamide, said tertiary formamide and said tertiary acetamide; b) reducing the concentration of tertiary acetamide in the crude recycle solvent stream by reacting at least a portion of the tertiary acetamide with a chlorinating agent selected from the group consisting of chloroiminium species, acyl chlorides phosphorus chlorides and sulfur chlorides to provide a purified recycle solvent stream; and c) recycling said purified recycle solvent stream as a reaction vehicle.