4-Methyl-2-Pentanone CAS 108-10-1

CN201210221816.8 discloses a method for preparing 2-(4-oxyphenoxy) propionic acid, comprising the following steps: mixing 183 parts by weight of hydroquinone and 202.5 parts by weight of methyl S-2-chloropropionate Put it into the reaction kettle, add 100 parts by weight of sodium hydroxide in the first batch, heat the reaction kettle to 70-81 ° C and keep it for 8 hours, after the reaction is completed, lower the temperature of the reaction kettle to room temperature; then add 128 parts by weight of hydrochloric acid to the reaction kettle again , keep the pH value of about 5~6, in a weakly acidic environment, excess sodium hydroquinone reacts with hydrochloric acid to produce hydroquinone; add extractant 4-methyl-2-pentanone to the reactor, the solution Layering, the organic layer is hydroquinone and extractant, the water layer is intermediate A/B, methanol and salt solution; the organic phase mixture is separated, 4-methyl-2-pentanone is distilled under reduced pressure, and p-benzene is centrifuged. Diphenol crystals; 128 parts by weight of hydrochloric acid were added dropwise to the water phase after the dealcoholation, the pH value was adjusted to 1~2, the intermediate reacted under the acid precipitation condition, and 2-(4-oxyphenoxy group was precipitated after adding the acid) ) propionic acid. The invention has the advantages of simple operation, low cost and less pollution, and is suitable for large-scale industrial application.

CN201310265574.7 discloses a method for purifying tiamulin fumarate. The process steps are as follows: first, neutralize tiamulin base with methanol and fumaric acid to form a salt, and then centrifuge the obtained crude product into 4-methyl In -2-pentanone, keep the temperature at 40~60°C for 90~110min under stirring, then rapidly cool down to -20~-10°C, keep the temperature for 90~110min, and centrifuge again. The obtained fine product is put into a double cone rotary vacuum dryer, After drying until the moisture content of the material is less than or equal to 0.5%, it can be sieved and packaged. The invention simplifies the domestic conventional refined tiamulin fumarate production process, adopts MIBK (4-methyl-2-pentanone) to replace butyl acetate or acetone, reduces organic solvent consumption, improves safety factor, and reduces potential safety hazards; shortens production Cycle, improve crystallization quality and yield, reduce energy consumption, improve production efficiency, and have certain development prospects.