反应详情

温度

25 °C

208 parts of dried crude 6-n-propoxy-3-acetylamino-aniline obtained according to Example 7 of European Pat. No. 0,011,048 (containing, in addition to 190.3 parts of target product, 8.8 parts of 2,4-bis-acetylamino-1-n-propoxybenzene and 3.5 parts of 2,4-diamino-1-n-propoxybenzene, as well as small amounts of magnesium acetate and oxidative decomposition products) are dissolved in 300 parts of ethanol at 50° C., with stirring, and, after the solution has been cooled to 25° C., 170 parts of 48% strength hydrobromic acid are added dropwise in the course of 1.5 hours. The precipitate which has separated out is filtered off with suction at 0°-5° C., washed with two portions of 60 parts of ethanol and dried in vacuo. 257.1 parts of 6-n-propoxy-3-acetylamino-aniline hydrobromide (no impurities detectable by HPLC, purity by diazotization: 99.4%) are obtained, which corresponds to a yield of 88.9% of theory (based on the crude feed product) or 97.2% of theory (based on the target product contained therein).

1. dry with material208 parts of dried crude 6-n-propoxy-3-acetylamino-aniline
2. customobtained
3. customThe precipitate which has separated out
4. filtrationis filtered off with suction at 0°-5° C.
5. washwashed with two portions of 60 parts of ethanol
6. customdried in vacuo