4-Hydroxyphenylacetic acidtuaj yeem tau txais los ntawm cov txheej txheem hluavtaws hauv qab no:
1. Styrene oxidation txoj kev:
Styrene tuaj yeem oxidized los tsim 4-hydroxyphenylacetic acid. Styrene yog reacted nrog hydrogen peroxide ntawm qhov kub thiab txias los tsim 4-hydroxyphenylacetic acid. Cov kauj ruam tshwj xeeb yog raws li hauv qab no:
(1) Muab styrene (1.0 mol), benzoyl peroxide (0.05 mol) thiab catalyst (xws li ammonium vanadate, sodium vanadate, thiab lwm yam) rau hauv cov tshuaj tiv thaiv kettle.
(2) Ntxiv rau qhov tsim nyog cov pa oxygen rau hauv cov tshuaj tiv thaiv kab mob, tom qab ntawd tsa cov tshuaj tiv thaiv kub rau 80-90 degree , thiab hnov mob rau 2-3 teev.
(3) Tom qab cov tshuaj tiv thaiv, txias cov tshuaj tiv thaiv rau hauv chav sov, ntxiv cov dej kom tsim nyog thiab kho cov pH kom nyob ib puag ncig nruab nrab, kom 4-hydroxyphenylacetic acid tuaj yeem ua rau tag nrho hauv dej.
(4) Tom qab lim cov dej nag, ntxuav nrog dej thiab ziab kom tau txais 4-hydroxyphenylacetic acid cov khoom uas muaj purity siab dua.
2. Phthalate decarboxylation txoj kev:
Phthalic acid dhau mus decarboxylation los tsim 4-hydroxyphenylacetic acid.
(1) Muab 4-hydroxyphenylacetic acid (1.0 mol) thiab phthalic acid (1.1 mol) rau hauv cov tshuaj tiv thaiv kettle.
(2) Ntxiv qhov tsim nyog ntawm cov catalyst (xws li molybdenum trioxide, hydrogen peroxide, thiab lwm yam) thiab cov kuab tshuaj tsim nyog (xws li dej, ethanol, thiab lwm yam) rau hauv cov tshuaj tiv thaiv hluav taws xob.
(3) Ua kom cov tshuaj tiv thaiv kub rau 120-140 degree, hnov mob rau 6-8 teev, thiab ua kom nplawm thaum cov tshuaj tiv thaiv.
(4) Tom qab cov tshuaj tiv thaiv, txias cov tshuaj tiv thaiv rau hauv chav tsev kub, thiab ntxiv cov kua qaub los yog alkali tsim nyog los kho tus nqi pH, kom 4-hydroxyphenylacetic acid yog tag nrho precipitated hauv dej.
(5) Tom qab lim cov dej nag, ntxuav nrog dej thiab ziab kom tau txais 4-hydroxyphenylacetic acid cov khoom uas muaj purity siab.
Nws yuav tsum raug sau tseg tias kev sib txuas ntawm 4-hydroxyphenylacetic acid los ntawm decarboxylation ntawm phthalic acid yuav tsum tau xaiv cov catalysts thiab cov kuab tshuaj uas tsim nyog, nrog rau cov tshuaj tiv thaiv kub thiab lub sijhawm, thiab cov xwm txheej no yuav cuam tshuam cov nyhuv ntawm cov tshuaj tiv thaiv thiab purity. ntawm cov khoom. Tsis tas li ntawd, kev nplawm tas li yuav tsum tau ua thaum lub sij hawm cov tshuaj tiv thaiv kom paub meej tias cov tshuaj tiv thaiv tau zoo ib yam.
3. Methyl phthalate txo txoj kev:
Methyl phthalate tau txais cov tshuaj tiv thaiv catalytic hydrogenation txo los tsim 4-hydroxyphenylacetic acid, thiab cov kauj ruam tshwj xeeb yog raws li hauv qab no.
(1) Siv methyl phthalate (1.2 mol) thiab hydrogen (6-8 atm) rau hauv cov tshuaj tiv thaiv kettle.
(2) Ntxiv cov catalyst tsim nyog (xws li palladium carbon, platinum carbon, thiab lwm yam) thiab cov kuab tshuaj tsim nyog (xws li ethanol, methanol, thiab lwm yam) rau hauv lub reactor.
(3) Ua kom cov tshuaj tiv thaiv kub rau 50-80 degree , thiab hnov mob rau 8-10 teev. stirring yog yuav tsum tau thaum lub sij hawm cov tshuaj tiv thaiv.
(4) Tom qab cov tshuaj tiv thaiv, txias cov tshuaj tiv thaiv rau hauv chav tsev kub, thiab ntxiv cov kua qaub los yog alkali tsim nyog los kho tus nqi pH, kom 4-hydroxyphenylacetic acid yog tag nrho precipitated hauv dej.
(5) Tom qab lim cov dej nag, ntxuav nrog dej thiab ziab kom tau txais 4-hydroxyphenylacetic acid cov khoom uas muaj purity siab.
4. Styrene hydroxylation txoj kev:
Styrene tuaj yeem ua hydroxylated nyob rau hauv muaj cov poov tshuaj permanganate los tsim 4-hydroxyphenylacetic acid. Cov kauj ruam tshwj xeeb yog raws li hauv qab no:
(1) Siv styrene (1.0 mol), hydrogen peroxide (30 feem pua H2O2) thiab catalyst (xws li ammonium vanadate, thiab lwm yam) rau hauv cov tshuaj tiv thaiv kettle.
(2) Ntxiv qhov tsim nyog cov kuab tshuaj (xws li ethanol, dej, thiab lwm yam) rau hauv cov tshuaj tiv thaiv kettle.
(3) Ua kom cov tshuaj tiv thaiv kub rau 60-80 degree, hnov mob rau 6-8 teev, thiab ua kom nplawm thaum cov tshuaj tiv thaiv.
(3) Tom qab cov tshuaj tiv thaiv, txias cov tshuaj tiv thaiv rau hauv chav sov, thiab ntxiv cov kua qaub los yog alkali tsim nyog los kho tus nqi pH, kom 4-hydroxyphenylacetic acid tuaj yeem ua rau tag nrho cov dej nag.
(4) Tom qab lim cov dej nag, ntxuav nrog dej thiab ziab kom tau txais 4-hydroxyphenylacetic acid cov khoom uas muaj purity siab dua.
5. Hydroxylation ntawm acetophenone:
Acetophenone tuaj yeem ua hydroxylated nyob rau hauv muaj hydrogen peroxide los tsim 4-hydroxyphenylacetic acid.
(1) Noj acetophenone (1.0 mol), hydrogen peroxide (30 feem pua H2O2) thiab catalyst (xws li ammonium vanadate, thiab lwm yam) rau hauv cov tshuaj tiv thaiv kettle.
(2) Ntxiv qhov tsim nyog cov kuab tshuaj (xws li ethanol, dej, thiab lwm yam) rau hauv cov tshuaj tiv thaiv kettle.
(3) Ua kom cov tshuaj tiv thaiv kub rau 60-80 degree, hnov mob rau 6-8 teev, thiab ua kom nplawm thaum cov tshuaj tiv thaiv.
(4) Tom qab cov tshuaj tiv thaiv, txias cov tshuaj tiv thaiv rau hauv chav tsev kub, thiab ntxiv cov kua qaub los yog alkali tsim nyog los kho tus nqi pH, kom 4-hydroxyphenylacetic acid yog tag nrho precipitated hauv dej.
(5) Tom qab lim cov dej nag, ntxuav nrog dej thiab ziab kom tau txais 4-hydroxyphenylacetic acid cov khoom uas muaj purity siab.
Nws yuav tsum tau muab sau tseg tias cov synthesis ntawm 4-hydroxyphenylacetic acid los ntawm hydroxylation ntawm acetophenone yuav tsum tau xaiv ib tug tsim nyog catalyst thiab hnyav, raws li zoo raws li cov tshuaj tiv thaiv kub thiab lub sij hawm, thiab tej yam no yuav cuam tshuam cov nyhuv ntawm cov tshuaj tiv thaiv thiab purity. ntawm cov khoom. Tsis tas li ntawd, kev nplawm tas li yuav tsum tau ua thaum lub sij hawm cov tshuaj tiv thaiv kom paub meej tias cov tshuaj tiv thaiv tau zoo ib yam. Nyob rau tib lub sijhawm, xyuam xim rau kev nyab xeeb ntawm kev ua haujlwm kom tsis txhob muaj xwm txheej tshwm sim los ntawm hydrogen peroxide to.
4-Hydroxyphenylacetic acid, tseem hu ua p-hydroxyphenylacetic acid, yog ib qho tseem ceeb organic compound. Nws muaj ntau yam tshuaj lom neeg tseem ceeb thiab tuaj yeem siv los npaj cov tshuaj sib txawv. Nov yog qee cov ntsiab lus hais txog cov khoom reactive ntawm 4-hydroxyphenylacetic acid.
Ua ntej tshaj plaws, pawg hydroxyl nyob rau hauv 4-hydroxyphenylacetic acid muaj zog electrophilicity thiab hauv paus, thiab tuaj yeem hnov mob nrog acids thiab acylating agents los tsim cov esters thiab cov khoom acylated. Piv txwv li, nws muaj peev xwm hnov mob nrog cawv los tsim cov khoom sib xws esterification rau kev npaj cov tshuaj tsw qab esters. Tsis tas li ntawd, 4-hydroxyphenylacetic acid kuj tuaj yeem ua rau cov kua qaub anhydride los ua cov khoom sib xws.
Qhov thib ob, pawg carboxyl nyob rau hauv 4-hydroxyphenylacetic acid kuj muaj zog reactivity, thiab muaj peev xwm ua tau esterification thiab midation tshwm sim nrog cawv thiab amines los tsim cov esters, amides thiab lwm yam khoom. Piv txwv li, nws muaj peev xwm hnov mob nrog ethanol los tsim cov khoom sib xws ester rau kev npaj cov tshuaj tsw qab esters.
Tsis tas li ntawd, 4-hydroxyphenylacetic acid kuj tuaj yeem txo qis rau phenols lossis oxidized rau aldehydes, ketones, thiab lwm yam los ntawm cov tshuaj tiv thaiv redox. Piv txwv li, nws tuaj yeem txo qis rau p-hydroxybenzaldehyde los ntawm kev txo cov tshuaj tiv thaiv rau kev npaj cov tshuaj sib txuas.
Thaum kawg, 4-hydroxyphenylacetic acid tuaj yeem nkag mus rau cov tshuaj tiv thaiv condensation nrog lwm cov tshuaj nyob rau hauv cov xwm txheej tsim nyog los tsim ntau yam khoom sib txawv. Piv txwv li, nws tuaj yeem raug cov tshuaj tiv thaiv acid-catalyzed condensation nrog styrene los tsim cov khoom xws li 3-styryl-4-hydroxyphenylacetic acid.