Kev tsim cov txheej txheem ntawm phenacetin
Oct 22, 2021
(1) Tau txais los ntawm acetylation ntawm p-aminophenethyl ether. Kev sib xyaw ntawm benzene, acetic anhydride thiab p-aminophenethyl ether yog rhuab azeotropically ntawm cov roj da dej rau 4 teev. Tom qab cov tshuaj tiv thaiv tiav, cov reactant txias, uas yog, phenatin yog precipitated, uas yog lim, ntxuav nrog txias benzene, thiab qhuav. Cov tawm los yog tus nqi theoretical. 86% ntawm nws.
(2) Muab tau los ntawm kev ua ntawm acetaminophen thiab sodium ethoxide: thawj zaug ntxiv p-acetamidophenol rau sodium ethoxide, tom qab ntawd maj mam ntxiv ethyl iodide, cua sov rau reflux rau 1h, txias thiab lim, thiab cov khoom siv crude yog yaj hauv ethanol. Tom qab lim dej, cov lim dej yog diluted nrog dej kub, tom qab ntawd txias, lim, thiab qhuav kom tau txais cov khoom tiav. Cov zis yog 80% ntawm cov nyiaj theoretical. Thawj txoj kev tuaj yeem siv acetic acid es tsis txhob siv benzene ua cov kuab tshuaj. Cov txheej txheem yog raws li nram no. Thaum tshav kub kub 40% dilute acetic acid rau boiling, muab tso rau hauv p-aminophenethyl ether, distilled tawm dej, ntxiv glacial acetic acid thaum kub nce mus rau 150 ° C, reflux rau 1h, mus rau chav tsev, tos kom txog thaum kub nce siab tshaj 150 ° C. C, coj mus kuaj thiab txiav txim siab dawb aminobenzene Diethyl ether, ntxiv acetic anhydride raws li qhov seem ntawm amino phenyl ethyl ether, reflux cov tshuaj tiv thaiv rau 0.5h, xyuas qhov kawg taw tes, depressurize tom qab dhau, thiab rov qab acetic acid kom txog thaum cov amino cov ntsiab lus yog. hauv qab 0.046 thiab cov ntsiab lus acid yog qis dua 0.2%, thiab cov tshuaj tiv thaiv yog hydraulically nias rau hauv cov kua dej kub refined niam. Do thiab txias rau 40 ℃, lim kom tau phenacetin crude. Refining, ntxiv boiling dej los yog refined niam cawv rau crude phenacetin, tshav kub thiab do kom dissolve, lim, kho cov filtrate nrog acid rau pH=4.5-4.7, ntxiv activated carbon thiab sodium thiosulfate thiab do kom decolorize, lim, txias cov filtrate. kom crystallize, co thiab lim, airflow qhuav, tau phenacetin.
