2, 5-Dihydroxybenzaldehydeyog ib qho organic compound nrog cov mis molecular C7H6O3 thiab CAS 1194-98-5. Nws yog ib lub teeb daj crystalline daim ntawv, feem ntau muaj nyob rau hauv hmoov los yog siv lead ua daim ntawv, nrog ib tug tshwj xeeb aldehyde saj, zoo li cov tsw ntawm iab almonds. Thaum lub sij hawm melting txheej txheem, nws yuav maj mam tig daj thiab sublimate ntawm kub kub. Nws tuaj yeem soluble hauv dej, tab sis nws cov solubility tsis siab. Nws kuj yog me ntsis soluble hauv cov kuab tshuaj organic xws li cawv thiab ethers. Cov tshuaj no muaj cov nplhaib benzene, pawg aldehyde, thiab pawg hydroxyl. Ntawm lawv, pawg aldehyde nyob rau ntawm qhov chaw nyob ib sab ntawm lub nplhaib benzene, thiab ob pawg hydroxyl nyob ntawm qhov nruab nrab ntawm lub nplhaib benzene. Nws yog ib qho kev txo qis uas tuaj yeem hnov mob nrog alkali los tsim cov phenolic ntsev. Nws tuaj yeem raug benzoin condensation cov tshuaj tiv thaiv nrog acetaldehyde nyob rau hauv acidic tej yam kev mob, ua benzoic acid.
(Cov khoom txuas: https://www.bloomtechz.com/synthetic-chemical/organic-intermediates/2-5-dihydroxybenzaldehyde-cas-1194-98-5.html)
Txoj Kev 1:
Kev npaj los ntawm phenol oxidation: Phenol tuaj yeem oxidized rau benzoquinone nyob rau hauv alkaline tej yam kev mob, thiab tom qab ntawd dhau mus rau Diels Alder cov tshuaj tiv thaiv nrog ethyl acetate kom tau 2, 5-dihydroxybenzoate ethyl ester. Thaum kawg, 2, 5-Dihydroxybenzaldehyde yog tau los ntawm acidic hydrolysis.
Cov kauj ruam ntxaws ntxaws rau kev npaj 2,5-Dihydroxybenzaldehyde los ntawm phenol oxidation yog raws li nram no:
Cov kauj ruam:
1. Ntxiv phenol thiab ethyl acetate rau hauv lub khob ntim dej, do thiab maj mam ntxiv poov tshuaj permanganate, thiab ntxiv sulfuric acid dropwise. Lub sijhawm no, qhov kub hauv lub khob yuav nce siab. Potassium permanganate reacts nrog phenol los tsim poov tshuaj benzoate thiab manganese dioxide.
2. Ntxiv qhov tsim nyog ntawm sodium hydroxide tov rau neutralize tshaj poov tshuaj permanganate thiab sulfuric acid, kom pH tus nqi ntawm cov tshuaj mus txog nruab nrab.
3. Txias cov tshuaj tiv thaiv rau hauv chav tsev kub, ces lim kom tshem tawm cov manganese dioxide generated precipitate.
4. Ntxuav cov txheej txheem saum toj kawg nkaus nrog ethyl acetate hauv qhov sib cais kom tshem tawm cov tsis muaj phenol thiab ethyl acetate, tom qab ntawd ntxiv cov tshuaj hydrochloric acid kom tsim nyog rau cov tshuaj pH acidic.
5. Thaum tshav kub kub cov tshuaj tiv thaiv rau lub xeev reflux, tso cai rau cov generated ethyl benzoate mus rau hydrolysis cov tshuaj tiv thaiv nyob rau hauv qhov kev txiav txim ntawm hydrochloric acid los tsim 2, 5-dihydroxyethyl benzoate.
6. Txias cov tshuaj tiv thaiv rau hauv chav tsev kub, ces lim kom tshem tawm cov generated sodium chloride precipitate.
7. Ntxuav cov organic txheej sab saud nrog ethyl acetate hauv qhov sib cais kom tshem tawm cov tshuaj hydrochloric acid uas tsis muaj kev cuam tshuam, thiab tom qab ntawd ua kem chromatography cais thiab ntxuav cov khoom 2, 5-Dihydroxybenzaldehyde.
Chemical Equation:
C6H5OH + KMnO4 + H2YOG4 → C6H5COOK + MnSO4 + H2O
C6H5COOK + NaOH → C6H5COV + KOH
C6H5COONa + HCl → C6H5COOH + NaCl
C6H5COV + CH3COOC2H5 → C6H5COOB3 + H2O
C6H5COOB3 + H2O → C6H5(OH) COJ3+ HCl
C6H5(OH) COJ3 → C6H5(OH)CHO + CH3OH
C6H5(OH)CHO + H2O → C6H5(OH)COOH + HCl
Nyob rau hauv cov txheej txheem saum toj no synthesis, thawj kauj ruam yog los tsim cov poov tshuaj benzoate los ntawm oxidation cov tshuaj tiv thaiv ntawm phenol thiab poov tshuaj permanganate nyob rau hauv qhov kev txiav txim ntawm sulfuric acid; Cov kauj ruam thib ob yog kom tsis txhob muaj cov poov tshuaj permanganate thiab sulfuric acid ntxiv los ntawm kev ntxiv sodium hydroxide tov; Qhov thib peb kauj ruam yog hydrolyze lub generated ethyl benzoate los ntawm kev ntxiv hydrochloric acid; Kauj ruam plaub yog cais thiab ntxuav cov khoom 2,5-Dihydroxybenzaldehyde los ntawm kab chromatography.
Txoj Kev 2:
Kev npaj los ntawm condensation cov tshuaj tiv thaiv ntawm phenol thiab formaldehyde: Phenol thiab formaldehyde tuaj yeem raug cov tshuaj tiv thaiv condensation los tsim phenolic resin nyob rau hauv alkaline tej yam kev mob. Los ntawm kev tswj cov tshuaj tiv thaiv thiab kev siv cov catalysts, high-purity 2, 5-Dihydroxybenzaldehyde tuaj yeem npaj tau.
Cov kauj ruam ntxaws ntxaws rau kev npaj 2,5-Dihydroxybenzaldehyde los ntawm cov tshuaj tiv thaiv condensation ntawm phenol thiab formaldehyde yog raws li nram no:
Cov kauj ruam:
1. Ntxiv phenol thiab formaldehyde rau hauv lub khob ntim dej, tom qab ntawd ntxiv cov tshuaj sodium hydroxide uas tsim nyog, do thiab maj mam ua kom sov cov tshuaj tiv thaiv rau lub xeev reflux. Lub sijhawm no, phenol thiab formaldehyde tau txais cov tshuaj tiv thaiv condensation nyob rau hauv alkaline tej yam kev mob los tsim 2, 5-dihydroxybenzaldehyde.
2. Tom qab cov tshuaj tiv thaiv tiav lawm, txias cov tshuaj tiv thaiv rau hauv chav sov, thiab tom qab ntawd ntxiv ib qho kev tsim nyog ntawm cov concentrated hydrochloric acid kom pH tus nqi ntawm cov tshuaj acidic.
3. Ntxuav cov txheej txheem saum toj kawg nkaus nrog cov tshuaj sodium carbonate hauv qhov sib cais kom tshem tawm cov phenol thiab formaldehyde uas tsis muaj kev cuam tshuam, thiab tom qab ntawd ua kem chromatography cais thiab ntxuav cov khoom 2,5-Dihydroxybenzaldehyde.
Chemical Equation:
C6H5OH + HHO → C6H5(OH) COJ
C6H5(OH)CHO + HCl → C6H5(OH)COOH + HCl
Nyob rau hauv cov txheej txheem synthesis saum toj no, thawj kauj ruam yog los tsim 2,5-dihydroxybenzaldehyde los ntawm cov tshuaj tiv thaiv condensation ntawm phenol thiab formaldehyde nyob rau hauv alkaline tej yam kev mob; Cov kauj ruam thib ob yog ua kom muaj cov tshuaj tiv thaiv acidolysis ntawm cov tsim tawm 2,5-dihydroxybenzaldehyde los ntawm kev ntxiv cov concentrated hydrochloric acid los tsim 2,5-dihydroxybenzaldehyde.
Txoj Kev 3:
Kev npaj los ntawm condensation cov tshuaj tiv thaiv ntawm formic acid thiab phenol: Nyob rau hauv acidic tej yam kev mob, formic acid thiab phenol muaj peev xwm undergo condensation cov tshuaj tiv thaiv los tsim benzoic acid. Tom qab ntawd benzoic acid tuaj yeem raug txo kom tau 2, 5-dihydroxybenzyl cawv. Thaum kawg, 2,5-dihydroxybenzyl cawv yog oxidized rau 2,5-dihydroxybenzaldehyde los ntawm cov tshuaj tiv thaiv oxidation.
Cov kauj ruam tshwj xeeb yog raws li nram no:
1. Kev npaj tshuaj tiv thaiv: Ntxiv ib qho tsim nyog ntawm formic acid thiab phenol rau lub khob ntim hauv qab thiab xyuas kom meej tias lawv muaj cov solubility zoo hauv cov kuab tshuaj. Cov kuab tshuaj tsim nyog, xws li ethanol lossis ether, tuaj yeem raug xaiv los ua kom tiav cov tshuaj reactants.
2. Cov tshuaj tiv thaiv condensation: Maj mam ntxiv cov tshuaj sodium hydroxide uas tsim nyog thaum nplawm. Nyob rau lub sijhawm no, formic acid thiab phenol tau txais cov tshuaj tiv thaiv condensation nyob rau hauv cov xwm txheej alkaline. Raws li cov tshuaj tiv thaiv no yog cov tshuaj tiv thaiv exothermic, nws yog ib qho tsim nyog los tswj cov tshuaj tiv thaiv kub kom tsis txhob muaj cua sov hauv zos. Khaws cov tshuaj tiv thaiv ntawm qhov kub kom haum rau cov tshuaj tiv thaiv condensation kom txog thaum cov tshuaj tiv thaiv tiav.
3. Acid hydrolysis: Tom qab cov tshuaj tiv thaiv condensation tiav, txias cov tshuaj tiv thaiv rau hauv chav sov. Tom qab ntawd maj mam ntxiv qhov tsim nyog ntawm cov concentrated hydrochloric acid kom cov pH ntawm cov tshuaj acidic. Nyob rau hauv acidic tej yam kev mob, cov generated 2,5-dihydroxybenzoic acid tau txais ib tug hydrolysis cov tshuaj tiv thaiv, ua 2,5-dihydroxybenzaldehyde. Khaws cov tshuaj tiv thaiv nyob rau hauv acidic tej yam kev mob rau hydrolysis cov tshuaj tiv thaiv kom txog thaum cov tshuaj tiv thaiv tiav.
4. Kev sib cais thiab kev ua kom huv: Tom qab cov tshuaj tiv thaiv hydrolysis tiav, txias cov tshuaj tiv thaiv rau hauv chav sov. Tom qab ntawd, kem chromatography tau ua los cais thiab ntxuav cov khoom 2, 5-Dihydroxybenzaldehyde. Cov kauj ruam tshwj xeeb chromatographic sib cais yuav txawv nyob ntawm qhov kev sim, tab sis feem ntau suav nrog kev tso cov tshuaj tiv thaiv rau hauv kem chromatography ntaus ntawv, xaiv qhov tsim nyog rau elution, sau cov eluent thiab evaporating nws rau concentration.
5. Tom qab kev kho mob: Cov tshuaj concentrated yog lub tshuab nqus tsev vacuum uas siv lub tshuab nqus tsev vaporator lossis lwm yam khoom siv evaporation kom tau txais high-purity 2,5-Dihydroxybenzaldehyde. Yog xav tau kev lim dej ntxiv, kem chromatography tuaj yeem rov ua dua lossis siv lwm txoj hauv kev purification.
Chemical Equation:
Formic acid thiab phenol tau txais cov tshuaj tiv thaiv condensation nyob rau hauv alkaline tej yam kev mob los tsim 2, 5-dihydroxybenzoic acid:
HLO + C6H5OH → HCO6H5 + H2O
Nyob rau hauv acidic tej yam kev mob, 2,5-dihydroxybenzoic acid tau dhau los ua cov tshuaj tiv thaiv hydrolysis los tsim 2,5-Dihydroxybenzaldehyde thiab dej:
HCOOC6H5 + HCl → C6H5(OH)CHO + HCl
Nws yuav tsum tau muab sau tseg tias sib txawv synthesis txoj kev yuav xav tau cov raw khoom sib txawv, tej yam kev mob, thiab purification txoj kev. Yog li ntawd, hauv kev ua haujlwm zoo, nws yog ib qho tsim nyog los xaiv txoj kev tsim nyog rau kev sib xyaw ua ke raws li qhov xwm txheej tshwj xeeb. Nyob rau tib lub sijhawm, thaum ua cov kev sim tshuaj, nws yuav tsum tau ua tib zoo saib xyuas kev nyab xeeb ntawm kev sim, ua raws li cov cai hauv chav kuaj, thiab hnav cov kev tiv thaiv xws li cov khaub ncaws hauv chav kuaj thiab tsom iav.