| 摘要 |
FIELD: chemistry.SUBSTANCE: starting substances used are thiosemicarbazide, acetic anhydride, sodium hydroxide, monochloroacetic acid; the liquid medium used is 95% ethanol and purified water, wherein the thiosemicarbazide is dissolved in the purified water, the reaction mass is cooled to 0°C±0.5°C and while mixing, acetic anhydride is added at such a rate that temperature of the reaction mass does not rise above 4°C; after adding all the acetic anhydride, the mass is mixed for another 20-30 minutes at temperature not higher than 1°C±1°C; the precipitate is filtered, washed with cooled water (2-4°C), pressed and the purified water and the obtained moist precipitate are then placed in a round-bottom flask with a mixer; while stirring for 0.5-1 hours, sodium hydroxide solution is added to the reaction mass and then boiled for 1 hour; the monochloroacetic acid is then added to water, stirred for 30 minutes and boiled for 1 hour, cooled to 2-4°C; the precipitate is filtered, washed with cold water thrice and twice with cold 95% ethanol; the obtained moist precipitate is transferred into the round-bottom flask with a mixer; 95% ethanol is added, stirred and while stirring, morpholine solution is added to 95% ethanol, boiled while stirring for 30 minutes and then cooled to 85-90°; activated carbon is added, boiled for 10-20 minutes; the carbon is filtered, the filtrate is cooled to 4-5°C, the precipitate of the end product is filtered, washed with 95% ethanol and dried at 50-70°C.EFFECT: high output of the end product, high quality of said product, cheap production and faster process.1 cl, 1 ex |
