4-Bromo-3-fluorobenzoic acid CAS # 153556-42-4
Cov ntaub ntawv siv
| Siv | 4-bromo-3-fluorobenzoic acid yog ib qho tseem ceeb tshuaj raw khoom uas yuav siv tau los npaj ntau yam tshuaj (xws li tshuaj tiv thaiv kab mob benzamit). |
| Synthesis method | 4-bromo-3-fluorobenzoic acid tuaj yeem tau txais los ntawm oxidation ntawm 4-bromo-3-fluorotoluene los ntawm poov tshuaj permanganate. (1) oxidation: 100kg ntawm kg4-bromo -3-fluorotoluene, 120kg dej thiab 0.1kg ntawm fatty cawv polyether sodium sulfate (AES) sequentially ntxiv rau lub K-400L iav-lined tshuaj tiv thaiv kettle (tsim los ntawm Jiangsu industrial hauv ob sab phlu tshuaj. khoom co., ltd.) nrog nplawm thiab cua sov thiab condensation reflux ntaus ntawv, ces 167kg ntawm poov tshuaj permanganate maj mam ntxiv nyob rau hauv nplawm, khaws cia rau hauv boiling lub xeev, thiab reacted rau 9 teev, nres cov tshuaj tiv thaiv tom qab cov tshuaj reflux tsis muaj roj hlaws dai; (2) Lim: lim cov tshuaj tiv thaiv uas tau txais nyob rau hauv cov kauj ruam (1) thaum kub kom tau cov filtrate uas muaj lub hom phiaj cov khoom 4-bromo -3-fluorobenzoic acid; (3) Tshem tawm cov poov tshuaj permanganate: Txhawm rau tshem tawm cov poov tshuaj permanganate ntxiv rau hauv cov lim dej, 0.1kg ntawm sodium sulfite yuav tsum tau ntxiv rau cov lim tau hauv qib (2), qhov sib ntxiv ntawm sodium sulfite yog raws li cov kua pob tshab nrog cov xim liab ntawm cov tshuaj. (4) acidification: nyob rau hauv lub stirring lub xeev, maj mam ntxiv cov tshuaj rau cov tshuaj tau nyob rau hauv kauj ruam (3) nrog ib tug concentration ntawm 12mol / L concentrated hydrochloric acid. Thaum tus nqi pH ntawm cov tshuaj yog 2.2, nres ntxiv cov concentrated hydrochloric acid thiab txuas ntxiv cov tshuaj tiv thaiv rau 30min. (5) crystallization: nyob rau hauv lub xeev stirring, cov tshuaj tau nyob rau hauv kauj ruam (4) yog txias rau 2 ° C, thiab cov crystals precipitated nyob rau hauv cov tshuaj yog 4-bromo-3-fluorobenzoic acid. Thaum lub sijhawm ua haujlwm, nws yuav tsum tau nplawm tas li, txwv tsis pub 4-bromo-3-fluorobenzoic acid yuav tsim cov khoom loj, uas nyuaj rau kev cuam tshuam nrog cov txheej txheem tom ntej; (6) Lim thiab ntxuav: Cov kua sib xyaw uas muaj 4-bromo-3-fluorobenzoic acid crystals tau nyob rau hauv kauj ruam (5) yog centrifuged kom tau ib lub ncuav mog qab zib lim uas yog cov khoom nyoos 4-bromo-3-fluorobenzoic acid, cov khoom nyoos yog ntxuav nrog dej ntshiab thiab centrifuged (siv lub centrifuge nrog ntxuav muaj nuj nqi) kom tau refined 4-bromo-3-fluorobenzoic acid; (7) Kev ziab: 4-bromo-3-fluorobenzoic acid cov khoom npaj rau hauv kauj ruam (6) yog qhuav ntawm 75 ° C rau 12 teev kom tau 197 kg4-bromo-3-fluorobenzoic acid, cov ntsiab lus ntawm ntau dua 98. %. |
Sau koj cov lus ntawm no thiab xa tuaj rau peb
