Production method: first chlorination with phenol to obtain 2,4-dichlorophenol, the latter in the presence of sodium hydroxide and chloroacetic acid condensation to form 2,4-D sodium salt, and then acidified into 2,4-D original drug. Another new process is to condense phenol and chloroacetic acid under alkaline conditions and then chlorinate.
Production method: 2,4-dichlorophenol and monochloroacetic acid in a NaOH solution heated to reflux to obtain sodium 2,4-dichlorophenoxyacetate, and then acidified with hydrochloric acid.
Production method: using phenol as raw material, first condensed with chloroacetic acid, chlorinated, or chlorinated and then condensed with chloroacetic acid to obtain the product. (1) The chlorination process after the first condensation. The phenol was placed in a reaction vessel, heated and melted, and 2.2 times (molar ratio) of sodium hydroxide and 1.2 times (molar ratio) of chloroacetic acid were successively introduced, and reacted at 100-110 ° C for 30 minutes. After the reaction product was cooled, it was neutralized with hydrochloric acid to precipitate phenoxyacetic acid in a yield of 82% or more.
Phenoxyacetic acid was slowly introduced into the chlorine gas at 1.4-1.6 times (molar ratio) at 65-90 ° C, and the chlorinated product was 2,4-difluorophenoxyacetic acid in a yield of 89%.
(2) The first chlorination and condensation process. The molten phenol is placed in a chlorinator and chlorine is passed at 45-65 ° C for about 8-9 h. The chlorination reaction ends when the relative density of the reaction mass reaches 1.406 (40 ° C). The reactant was added to a 30% sodium hydroxide solution while hot, and after heating to boiling, a sodium chloroacetate solution was added dropwise and refluxed for 4-5 hours. After slightly cooling, it was neutralized to pH 1-3 with 30% hydrochloric acid. The benzene was extracted with hot benzene and the organic layer was separated. After cooling, white crystals are precipitated, and the finished product is obtained by suction filtration and drying.
Production method: using phenol as raw material, first condensed with chloroacetic acid, chlorinated, or chlorinated and then condensed with chloroacetic acid to obtain the product.
First condensation after chlorination process
The phenol was placed in a reaction vessel, heated and melted, and 2.2 times (molar ratio) of sodium hydroxide and 1.2 times (molar ratio) of chloroacetic acid were successively introduced, and reacted at 100 to 110 ° C for 30 minutes. After the reaction product was cooled, it was neutralized with hydrochloric acid to precipitate phenoxyacetic acid in a yield of 82% or more.
At phenoxyacetic acid, a chlorine gas of 1.4 to 1.6 times (molar ratio) was slowly introduced at 65 to 90 ° C, and the chlorinated product was 2,4-dichlorophenoxyacetic acid, and the yield was 89%.
First chlorination and condensation process
The molten phenol is placed in a chlorinator, and chlorine is passed through at 45 to 65 ° C for about 8 to 9 hours. When the relative density of the reaction material reaches 1.406 (40 ° C), the chlorination reaction ends. The reactant was added to a 30% sodium hydroxide solution while hot, and after heating to boiling, a sodium chloroacetate solution was added dropwise, and refluxed for 4 to 5 hours. After slightly cooling, it was neutralized with 30% hydrochloric acid to a Ph value of 1-3. The benzene was extracted with hot benzene and the organic layer was separated. After cooling, white crystals were precipitated, and the product was obtained by suction filtration and drying.
- Baste roasts, stir soups and stews, serve sauces, and more with this set of heavy-duty serving spoons.
- Drain off liquid from wet foods with the slotted or perforated spoons, and pour sauce or gravy with the Solid Spoon.
- SLOTTED COOKING SPOON – This heat resistant, slotted spoon is great for removing foods from boiling water or hot oil. It has a flat nose and bowl shaped head for easier stirring and serving.
-
SAFE AND HEALTHY FOR YOUR FAMILY - We use these utensils ourselves and want the best for our family and yours. Our FDA-grade silicone is safety-tested, heat resistant up to 480°F, and guaranteed 100% BPA-free
Slotted Spoon,Kitchen Slotted Spoon,Silicone Slotted Spoon,Slotted Spoon With Handle
Yangjiang Homelife Industry & Trading Co., Ltd. , https://www.bettyhomelife.com