Bromide ion → Isosorbide

Participants

Reaction Steps

Finally, German published patent application No. P 27 51 934 and the corresponding U.S. Pat. No. 4,065,488 describe a process wherein isosorbide in a first step is esterified by reaction with a lower alkanoic anhydride, chloride or bromide, in particular acetic acid anhydride, to yield a mixture of isosorbide, isosorbide-2-acrylate, isosorbide-5-acylate and isosorbide-2.5-diacylate. In a second step, isosorbide is extracted from this mixture in order to avoid formation of isosorbide-2.5-dinitrate in the following nitration reaction which is dangerous as explosive. In a third step, the mixture of isosorbide-2-acylate, isosorbide-5-acylate and isosorbide-2.5-diacylate is subjected to nitration with nitric acid and the resulting mixture of isosorbide-2-acylate-5-nitrate, isosorbide-5-acylate-2-nitrate and isosorbide-2.5-diacylate is subjected to partial saponification resulting in a mixture of isosorbide-2-nitrate, isosorbide-5-nitrate and isosorbide. Isosorbide-5-nitrate finally is separated from this mixture by recrystallization from appropriate solvents. Thus, this process also is characterized by a multitude of reaction steps and has the further disadvantage that isosorbide contained in the mixture obtained in the first reaction step, has to be extracted in order to avoid the formation of the explosive isosorbide-2.5-dinitrate in the subsequent nitration reaction.

Provenance & Evidence