| 摘要 |
Unpurified 2-bromo-2-nitro-1,3-propanediol is used as the starting material for a process for the preparation of 5-bromo-5-nitro-1,3-dioxane from 2-nitro-1,3-propanediol without the use of an organic solvent on an industrial scale. This is carried out in such a way that in a first stage a mixture of bromine and aqueous hydrogen bromide solution is cooled and an aqueous solution of an alkali metal or an alkaline-earth metal salt of 2-nitro-1,3-propanediol is added at such a rate that, with cooling, the maximum reaction temperature does not exceed 30.degree.C, and then in a second reaction stage paraformaldahyde and sulfuric acid are added, left to react above room temperature, and the organic phase separated. |
