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Chemical Structure| 629-97-0 Chemical Structure| 629-97-0
Chemical Structure| 629-97-0

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Docosane is a straight-chain alkane that can be used to synthesize structural composite materials with thermal energy storage/release capabilities and also for preparing thermosensitive antipyretic analgesics.

4.5 *For Research Use Only! Not for Human Use. We Do Not Sell to Patients.

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Product Details of Docosane

CAS No. :629-97-0
Formula : C22H46
M.W : 310.60
SMILES Code : CCCCCCCCCCCCCCCCCCCCCC
English Name :N-docosane
MDL No. :MFCD00009348
InChI Key :HOWGUJZVBDQJKV-UHFFFAOYSA-N
Pubchem ID :12405

Safety of Docosane

Application In Synthesis of Docosane

* All experimental methods are cited from the reference, please refer to the original source for details. We do not guarantee the accuracy of the content in the reference.

  • Downstream synthetic route of [ 629-97-0 ]

[ 629-97-0 ] Synthesis Path-Downstream   1~19

  • 1
  • [ 4444-90-0 ]
  • [ 629-97-0 ]
YieldReaction ConditionsOperation in experiment
With tungsten(IV) sulfide; nickel sulfide at 300℃; Hydrogenation;
  • 2
  • [ 105-74-8 ]
  • [ 1120-21-4 ]
  • [ 629-97-0 ]
  • [ 821-95-4 ]
  • [ 3658-44-4 ]
  • [ 105443-61-6 ]
YieldReaction ConditionsOperation in experiment
In (2)H8-toluene at 86℃; other solvents (hexachloroacetone, Cl(CH2)2Cl, C6D6, n-C8H18), temperature; thermolysis of lauroyl peroxide; mechanism, polar/radical pathways; radical scavenging; effect of temperature, viscosity and solvent polarity on decomposition product yields;
  • 3
  • [ 143-07-7 ]
  • [ 830-96-6 ]
  • [ 629-97-0 ]
  • [ 3364-46-3 ]
  • [ 224790-27-6 ]
YieldReaction ConditionsOperation in experiment
1: 60% 2: 16% 3: 15% With sodium methylate In methanol at 0℃; anodic oxidation at Pt/C electrode;
  • 4
  • [ 310408-15-2 ]
  • [ 112-95-8 ]
  • [ 629-97-0 ]
  • [ 629-94-7 ]
YieldReaction ConditionsOperation in experiment
With lithium aluminium tetrahydride at 300℃;
  • 5
  • [ 91079-23-1 ]
  • [ 91-17-8 ]
  • [ 55045-07-3 ]
  • [ 1612241-62-9 ]
  • [ 91-17-8 ]
  • [ 91-17-8 ]
  • [ 91-20-3 ]
  • [ 119-64-2 ]
  • [ 111-65-9 ]
  • [ 111-84-2 ]
  • [ 124-18-5 ]
  • [ 112-40-3 ]
  • [ 629-62-9 ]
  • [ 112-95-8 ]
  • [ 629-97-0 ]
  • [ 630-01-3 ]
  • [ 74-82-8 ]
  • [ 142-82-5 ]
  • [ 629-50-5 ]
  • [ 1560-97-0 ]
  • [ 629-59-4 ]
  • [ 6418-41-3 ]
  • [ 1560-96-9 ]
  • [ 18435-22-8 ]
  • [ 1560-95-8 ]
  • [ 2882-96-4 ]
  • [ 544-76-3 ]
  • [ 629-78-7 ]
  • [ 6418-43-5 ]
  • [ 1560-92-5 ]
  • [ 593-45-3 ]
  • [ 629-92-5 ]
  • [ 1560-84-5 ]
  • [ 638-67-5 ]
  • [ 646-31-1 ]
  • [ 629-99-2 ]
  • [ 3892-00-0 ]
YieldReaction ConditionsOperation in experiment
With Dimethyldisulphide; hydrogen at 363℃; for 120h; 1 Experiment 1; A liquid feed mixture of 69.74 wt% decalin (C10H18), 0.26wt% dimethyl disulphide (DMDS) and 30wt% tallow oil was prepared. The tallow oil comprised fatty acid chains with 12 to 20 carbon atoms (including the carboxyl carbon), the bulk of the molecules having 16 or 18 carbon atoms in the fatty acid chain (including the carboxyl carbon). The liquid mixture was fed to a reactor as illustrated in Figure 4, operating at 363°C and 30 barg (3.1 MPa) pressure, at a feed-rate of 60mL/hour. A cobalt-molybdenum on alumina catalyst was used. The liquid hourly space velocity (LHSV) of the liquid feed over the catalyst was 4 h-1. A flow of hydrogen was also fed to the reactor, such that the ratio of H2 gas volume to liquid feedstock volume was maintained at a value of 200 Nm3/m3 (gas volume at 15.6°C and 1 atm). Reaction was maintained over a period of 5 days. Liquid samples were collected daily and analysed according to a chromatographic method described in ASTM D2887, and also by GCMS. Gaseous off-gas samples were analysed using gas chromatography. The quantity of liquid product was determined gravimetrically. Off-gas volume was measured using a wet-test flow meter. The mass balance calculated from the quantities of the identified components of the obtained liquid and gaseous products was 99% with 1% standard deviation. The carbon balance was 100% with 1% standard deviation.
  • 6
  • [ 143-07-7 ]
  • [ 629-97-0 ]
YieldReaction ConditionsOperation in experiment
Multi-step reaction with 3 steps 1: 65 percent / 30 percent aq. H2O2 / H2SO4 / 1 h / 10 °C / addition 10 to 20 deg C 2: 91 percent / pyridine / diethyl ether / 0.5 h / 10 °C / addition -20 deg C to -10 deg C 3: octanoic acid, NaOH / methanol / 15 - 30 °C / electrolysis: platinum electrodes, different pulse frequencies
Multi-step reaction with 2 steps 1.1: dmap; dihydrogen peroxide / dichloromethane / 0.25 h / -15 °C 1.2: 0 °C 2.1: copper acetylacetonate; tetramethylethylenediamine / N,N-dimethyl-formamide / 12 h / 40 °C / Schlenk technique; Inert atmosphere
75 % With Ru supported on TiO2 In acetonitrile at 25℃; Inert atmosphere; Irradiation; 22-23 Example 23: Add 11.6 mg lauric acid and 5.0 mg Ru/TiO2 with a Ru content of 1.0 wt.% into the photocatalytic reactor.The catalyst and 1.0 mL of acetonitrile were continuously evacuated and purged with nitrogen five times to replace the atmosphere of the reactor, and irradiated with 365nm LED (10W) at 25°C for 3 hours; after the decarboxylation coupling reaction was completed, the acetonitrile solvent was used to adjust the volume; The product was analyzed by GC, and the molar yield of the coupling product was calculated to be 75%.
  • 7
  • [ 2388-12-7 ]
  • [ 629-97-0 ]
YieldReaction ConditionsOperation in experiment
Multi-step reaction with 2 steps 1: 91 percent / pyridine / diethyl ether / 0.5 h / 10 °C / addition -20 deg C to -10 deg C 2: octanoic acid, NaOH / methanol / 15 - 30 °C / electrolysis: platinum electrodes, different pulse frequencies
Multi-step reaction with 2 steps 1: 88 percent / pyridine / diethyl ether / -10 °C 2: neat (no solvent) / 24 h / -78 °C / Irradiation
Multi-step reaction with 2 steps 1: 85 percent / pyridine / diethyl ether / -10 °C 2: neat (no solvent) / 24 h / -78 °C / Irradiation
Multi-step reaction with 2 steps 1: 90 percent / pyridine / diethyl ether / -10 °C 2: neat (no solvent) / 24 h / -78 °C / Irradiation
Multi-step reaction with 2 steps 1: 91 percent / pyridine / diethyl ether / -10 °C 2: 8 percent Chromat. / 5percent octanoic acid, 5percent sodium octanoate / methanol / square pulse electrolysis at different frequencies, photolysis, thermolysis, other temperature, other diacyl peroxides

  • 8
  • [ 661-19-8 ]
  • [ 629-97-0 ]
YieldReaction ConditionsOperation in experiment
92% With 4-methyl-benzoic acid methyl ester; tetrabutylammonium tetrafluoroborate In N,N-dimethyl-formamide at 60℃; for 6h; Electrolysis; Inert atmosphere;
Multi-step reaction with 2 steps 1: phosphorus; iodine 2: zinc; hydrochloric acid; glacial acetic acid
YieldReaction ConditionsOperation in experiment
1: 22.54% 2: 23.22% 3: 16.95% 4: 8.85% 5: 3.71% 6: 1.38% 7: 0.5% With triisobutylaluminum at 110 - 130℃; for 13h;
  • 10
  • [ 3041-23-4 ]
  • [ CAS Unavailable ]
  • [ 1070-00-4 ]
  • [ 111-65-9 ]
  • [ 124-18-5 ]
  • [ 112-40-3 ]
  • [ 112-95-8 ]
  • [ 629-97-0 ]
  • [ 630-01-3 ]
  • [ 110-54-3 ]
  • [ 629-59-4 ]
  • [ 544-76-3 ]
  • [ 593-45-3 ]
  • [ 646-31-1 ]
  • [ 630-02-4 ]
  • [ 638-68-6 ]
YieldReaction ConditionsOperation in experiment
1: 8.59% 2: 11.49% 3: 8.97% 4: 4.71% 5: 1.86% 6: 0.6% 7: 0.17% 8: 1.31% 9: 6.85% 10: 11.49% 11: 10.27% 12: 6.01% 13: 2.59% Stage #1: tri(octadecyl)aluminium; ethene; trioctylaluminum In toluene at 20 - 116℃; for 2.33333h; Stage #2: With sulfuric acid; water at 40℃;
  • 11
  • [ 3041-23-4 ]
  • [ CAS Unavailable ]
  • [ 112-95-8 ]
  • [ 629-97-0 ]
  • [ 630-01-3 ]
  • [ 593-45-3 ]
  • [ 646-31-1 ]
  • [ 630-02-4 ]
  • [ 638-68-6 ]
YieldReaction ConditionsOperation in experiment
1: 10.19% 2: 13.39% 3: 9.99% 4: 3.02% 5: 0.69% 6: 0.13% 7: 0.02% Stage #1: tri(octadecyl)aluminium; ethene In toluene at 20 - 116℃; for 2 - 3h; Stage #2: With sulfuric acid; water at 40℃;
  • 12
  • [ 112-95-8 ]
  • [ 629-97-0 ]
  • [ 630-01-3 ]
  • [ 593-45-3 ]
  • [ 646-31-1 ]
  • [ 630-02-4 ]
  • [ 638-68-6 ]
  • [ 112-92-5 ]
  • [ 629-96-9 ]
  • [ 593-50-0 ]
  • [ 661-19-8 ]
  • [ 506-51-4 ]
  • [ 506-52-5 ]
  • [ 557-61-9 ]
YieldReaction ConditionsOperation in experiment
1: 12.4% 2: 13.4% 3: 7.8% 4: 3.2% 5: 1% 6: 0.2% 7: 0.05% Stage #1: icosane; n-docosane; n-hexacosane; octadecane; tetracosane; octacosane; n-triacontane With oxygen at 30 - 50℃; for 3h; Stage #2: With sulfuric acid; water
  • 13
  • [ CAS Unavailable ]
  • [ 629-97-0 ]
  • [ 24219-37-2 ]
  • [ 53053-78-4 ]
  • [ 51502-63-7 ]
YieldReaction ConditionsOperation in experiment
9% In tetrahydrofuran 2 EXAMPLE 2 EXAMPLE 2 This example illustrates comparative results when the procedure of Example 1 is carried out without a cyanide catalyst. 0.7 g (2.6 mmoles) of dry docosane was added to 10 ml of a 1.18M solution of dioctylmagnesium (11.8 mmoles) in THF. 1.5 ml of a 2.6M solution of MeSiCl3 (3.9 mmoles) in THF was added over a 40 minute period at 10°. After an additional two hours at 10° the yield of MTOS based on added MeSiCl3 was about 4%. After an additional 16 hours at room temperature, the yield of MTOS was about 14%, while the yield of the intermediate product methyldioctylsilyl chloride was about 9% and the yield of the byproduct methyldioctylsilyl hydride was about 58%.
  • 14
  • [ 629-97-0 ]
  • [ CAS Unavailable ]
  • [ 7732-18-5 ]
  • [ CAS Unavailable ]
YieldReaction ConditionsOperation in experiment
66% With heptanoic acid In xylene under N2, Schlenk techniques; H2O (0.31 mmol) added to anhyd. soln. of n-C22H46 (0.014 mmol), Eu complex (0.10 mmol) and heptanoic acid (0.51 mmol) in p-xylene; mixt. stirred at 200°C for 3 min; stored at ambient temp. for 4 d; crystals washed with toluene and hexane; dried under vac.; elem. anal.;
YieldReaction ConditionsOperation in experiment
for 120 - 480h; A Biodegradation of Ozonated Column Effluent; The biodegradability of the ozonated column effluent was tested by incubating the effluent over a 20-day period throughout which the COD and BOD of the flasks were monitored. FIG. 8 shows the measurements taken after 0, 5, 10, 15, and 20 days. The results indicated an increase of BOD from 0 to 4.2 mg/L during the first 10 days and leveling off over the remaining. The measured COD exhibited a complimentary curve showing a decrease in COD from 7.0 mg/L to 3.1 mg/L over the first 10 days and a constant level afterward. These results suggested that biodegradable organic compounds in the effluent were biodegraded over the first 10 days. The BOD curve was fitted with first-order kinetics using the least-square method with a first-order rate constant k0=0.243 day-1 and an ultimate BOD L0=4.25 mg/L. The obtained value of k0 approximates closely that of domestic wastewater routinely treated by biological unit processes.The acute aqueous toxicity during the 20-day incubation period was also monitored using a standard effluent toxicity test (HACH, 1988-1995b). FIG. 9 shows the percentage inhibition value (% inhibition) of the incubated samples over the same intervals. The measurements registered inhibition values within +/-10% that was within the nontoxic range of the method. This means that the effluent was nontoxic to the receiving E-Coli bacteria, and that the effluent contained biodegradable intermediates and byproducts, including biodegradation products, which possessed no acute toxic effects to the bacteria.Concurrent to measurements of COD, BOD, and toxicity was the GC/FID/MS identification of various intermediates and byproducts present in the flask over the same incubation period. FIG. 10 shows compounds found after 0, 5, 10, 15, and 20 days of incubation. The changes of speciation in the incubated effluent are more clearly tracked by Table A-III. The disappearance of 11 intermediates, including species 1, 3, 7, 8, 10, 13, 15, 16, 19, 21, and 22, during the first 5 days of incubation was most notable. Dissolved parent compound pyrene (1) and intermediates dialdehyde (2), tetraaldehyde (3), and other benzenedicarboxylic acids either disappeared or decreased in concentrations over the incubation period. The significant disappearance of many intermediates in the first 5 days is consistent with the much more rapid changes in BOD and COD during the initial period. After 5 days, virtually all other compounds remained detectable throughout the incubation, which signaled that these compounds could not be further biodegraded, consistent with relatively mild changes in BOD and COD. Also detected after 15 and 20 days was the phosphoric acid tributyl ester with a structure similar to high-energy phosphoanhydride bonds, which indicated that biosynthesis of ATP might have occurred along with the biodegradation processes.
  • 16
  • [ 129-00-0 ]
  • [ 85-44-9 ]
  • [ 90-47-1 ]
  • [ 629-62-9 ]
  • [ 629-97-0 ]
  • [ 630-01-3 ]
  • [ 629-59-4 ]
  • [ 544-76-3 ]
  • [ 112-34-5 ]
  • [ 97-87-0 ]
  • [ 629-94-7 ]
  • [ 638-67-5 ]
  • [ 646-31-1 ]
  • [ 629-99-2 ]
  • [ 203-63-4 ]
  • [ CAS Unavailable ]
  • [ 128-37-0 ]
  • [ 84-66-2 ]
  • [ 84-74-2 ]
  • [ 203-64-5 ]
  • [ 85-68-7 ]
  • [ 4371-26-0 ]
  • [ 16162-34-8 ]
  • [ 57-10-3 ]
  • [ 55045-10-8 ]
YieldReaction ConditionsOperation in experiment
With oxygen; ozone In water for 0.25 - 2h; A Example A; Degradation of pyrene; This example focuses on an integrated approach for the degradation of pyrene involving chemical oxidation followed by biological treatment. The objectives were to: 1) provide mechanistic details in the degradation of pyrene subject to ozone treatment, 2) test the combined technique of ozone pretreatment followed by biological degradation, and 3) test a pretreatment column to promote efficient use of chemical oxidants and biodegradability. Batch and packed column reactors were used to examine the degradation pathways of pyrene subject to ozonation in the aqueous phase. After different ozonation times, samples containing reaction intermediates and byproducts from both reactors were collected, identified for organic contents, and further biologically inoculated to determine biodegradability. The O3-pretreated samples were incubated for 5, 10, 15, and 20 days, after which biochemical oxygen demand (BOD), chemical oxygen demand (COD), and toxicity tests along with qualitative and quantitative GC/FID and GC/MS analyses of pyrene, intermediates, and products were performed. Intermediates identified at different stages included 4,5-phenanthrenedialdehyde, 2,2',6,6'-biphenyltetraaldehyde, and long-chain aliphatic hydrocarbons, which suggested that the degradation of pyrene was initiated by O3 via ring cleavage at the 4,5- and 9,10-bonds and that further oxidation ensued via reactions with both O3 and OH. until complete mineralization. Intermediates formed during chemical oxidation were biodegradable with a measured first-order rate constant (k0) of 0.243 day-. The integrated chemical-biological system appeared to be feasible for treating recalcitrant compounds, and a chemical pretreatment column was particularly useful in promoting soluble intermediates from otherwise highly insoluble, inaccessible pyrene.Materials and MethodsChemicalsOzone (1% w/w ozone in air) was generated from filtered, dry air by an ozonator (Model T-816, Polymetrics Corp.). Pyrene (99%, Aldrich Chemical Co.) was washed with distilled-deionized (DD) water three times, extracted by dichloromethane (DCM), and the solvent evaporated by a gentle stream of nitrogen gas. Stock and working indigo blue solutions were prepared from potassium indigo trisulfonate (C16H7N2O11S3K3, Aldrich Co.) per Standard Methods (APHA et al., 1992a). Polyseed (Hach Co.) was used in dilution water for biochemical oxygen demand (BOD) measurements per Standard Methods (APHA et al., 1992b). Inoculum for toxicity test was prepared according to a Hach method (HACH, 1988-1995b). COD digestion solutions (0-15,000 mg/L, 0-40 mg/L range, Hach Co.), ToxTrak reagent powder pillows, and ToxTrak accelerator solution (Hach Co.) were purchased and used according to the manufacturer's methods without further processing. Low-organic (<15 ppb as TOC), low-ion (resistivity>18 MΩ-cm), and non-pyrogenic (up to 4-log reduction with reverse osmosis pretreatment) DD water was used in all procedures (4-stage Mill-Q Plus system, Millipore Co.). Dichloromethane (Fisher Scientific) of HPLC grade was used in liquid-liquid extraction procedures. Other chemicals used in this research were of reagent grade.; Results and Discussion; Ozonation of pyrene was carried out in batch and column reactors to study: 1) the effect of reactor on intermediates and products formation, 2) the degradation pathway of pyrene under ozonation, 3) the biodegradability of intermediates, and 4) the feasibility of a combined chemical-biological treatment system for pyrene. Reaction solutions during ozonation and biodegradation processes at different stages were collected and the intermediates and byproducts identified by GC/MS techniques.1. Effects of the Reactor Type on Intermediates and Products FormationTo delineate the influence of reactor configurations on the formation of intermediates and products, ozonation experiments using aqueous and excess pyrene were carried out in batch and packed column reactors. BOD5 and COD were measured for three ozonated, filtered solutions: 1) a saturated aqueous solution of pyrene (0.13 ppm), 2) the solution after ozonation of an excess pyrene suspension (1 g/1.7 L), and 3) the effluent of a column packed with excess pyrene solid (1 g) and glass beads (7.5 in. in bed-length). The saturated pyrene solution was prepared by allowing excess pyrene solid to reach dissolution equilibrium in water overnight followed by removal of the excess solid using a 0.45-μm filter. The ozonated batch solution was obtained after 10 min of ozonation and filtered, while the effluent was collected from the packed column fed with ozonated water over a 4-hr period. Table A-I shows the results of BOD5 and COD measurements. The BOD5 for the saturated pyrene solution approximates over 80% of the COD value, suggesting that pyrene in its dissolved form is amenable to biodegradation, albeit in small quantity. The aqueous phase COD from the ozonated batch reactor increased after ozonation possibly due to occurrence of intermediates or pyrene-derivatives that are more soluble in water as a result of ozonation. The new, lower BOD5/COD ratio of 66% appeared to suggest either that a larger amount of degradable substrates was available after ozonation that resulted in lower BOD5, or more likely that the biodegradability of the ozonated solution decreased as a result of ozonation possibly due to formation of slightly more recalcitrant intermediates. Following the reasoning of increased aqueous COD due to abundance of more soluble intermediates, the measured COD for column effluent would imply that it contained much more intermediates and byproducts. The new BOD5/COD ratio registered a slightly smaller value of 0.53. These ratios are well within those commonly observed for domestic wastewater and do not seem to signify toxicity.Parallel to BOD5 and COD measurements of the ozonated reaction media, the effects of reactors on intermediates formation were further probed using GC/FID and GC/MS identification techniques. FIG. 2 shows the gas chromatograms of parent and identified intermediate compounds in 1) the aqueous pyrene solution without ozonation, 2) ozonated column effluent, and 3) ozonated batch solution. Despite its low solubility, the parent pyrene (peak 1 as labeled) was found in all solutions. As listed in Table A-II, twenty-five other compounds were found in the column effluent, and except for two of them were identifiable by MS library comparison. Two important intermediates 4,5-phenanthrenedialdehyde (species 2) and 2,2',6,6'-biphenyltetraaldehyde (species 2) were found in the ozonated column effluent but not in the ozonated batch solution. The mass spectra of these two intermediates, species 2 (m/z 234) and 3 (m/z 266), are shown in FIGS. 3(a) and (b), respectively.In the ozonated batch solution, found in place of the di- and tetra-aldehydes was a variety of benzenediacarboxylic acids, which apparently are subsequent byproducts in the oxidative chain of events. Comparison of gas chromatograms (b) and (c) of FIG. 2 shows that the column effluent contained an abundance of intermediates (such as species 2 and 3) whereas the ozonated batch solution contained less intermediates but more fragments that were products further down the degradation process. These identifications are consistent with the higher COD measurement in the column effluent than that in the batch solution.These results indicated that ozone was capable of degrading pyrene via ring opening, as evidenced by intermediates dialdehyde and tetraaldehyde (species 2 and 3 in the column effluent), and further oxidation by ozone (and other oxygenated radicals to be discussed) to other fragments and byproducts (such as 1,2-benzenedicarboxylic acid, diisooctyl 4, benzylbutyl phthalate 5, hexacosane 23, henicosane 20, and nonyl phenol 13 in the batch solution) if the intermediates were to remain exposed to ozone. These results underscored the importance of the role that the reactor configuration played in determining the kinds and amounts of intermediates and byproducts to be found after ozonation. The influence of a column reactor on the types and amounts of intermediates and byproducts formed are illustrated in FIG. 4. A batch reactor readily subjects the intermediates from pyrene to continual O3 attack and further degradation, whereas the column reactor allows the intermediates to be eluted from the O3-rich area, i.e., the reactive zone. Thus, to promote the formation of intermediates that could be subsequently biodegraded rather than relying upon ozone as the sole oxidant in the complete degradation of pyrene, a column reactor was used to collect effluent that was rich in partially treated intermediates for further mechanistic and biodegradability studies.Degradation Pathway of Pyrene in Ozonated WaterThe effluent from a pyrene-packed column fed with ozonated water was collected and identified for intermediates and byproducts via GC/FID and GC/MS. The up-flow influent water contained 5 mg/L O3 while the effluent none, indicating that complete consumption of O3 occurred in the column. The filtered (through 0.45 μm) effluents exhibited yellowish intermediate compounds that were not apparent in previous samples from ozonated batch solutions. The absence of colored compounds in the batch reaction was attributed, as explained previously, to continual degradation of the colored intermediates by O3. FIG. 5 identified species found in the effluents collected at different time intervals. These identified species, including the dialdehyde (2) and tetraaldehyde (3) intermediates, resembled those identified in FIG. 2. In addition to the molecular ion peaks, other fragments including m/z 205, 176 and 29 corresponding to the loss of -CHO groups were noticeable in the mass spectra in the case of 4,5-phenanthrenedialdehyde, and m/z 237, 29 of 2,2',6,6'-biphenyltetraaldehyde. A biphenyl fragment was found at m/z 152 in FIG. 3(b), which suggested the presence of a biphenyl structure as 2,2',6,6'-biphenyltetraaldehyde.FIG. 2a showed a substantial variety of (unozonated) compounds eluted from the column even prior to the start of ozonation. These compounds were in many cases similar to that after ozonation as shown in FIG. 5a. This was attributed to the occurrence of autooxidation (reaction with molecular oxygen), which is also an oxidation process albeit at a much slower rate than of oxidation by ozone, resulting in similar intermediates and products. Autooxidation of pyrene could have occurred during storage on the shelf or by dissolved oxygen after being dispersed and thinly packed in the column. The latter was more likely as calibration runs prior to column loading did not reveal the intermediates. However, clearly discernable was that these intermediate and product peaks intensified pronouncedly after the ozone oxidant was introduced, as evident in comparison of FIG. 5a with FIG. 2a. Data estimation suggested that oxygenated compounds such as 5, 8, 9, 11, 12, 13, and 16 increased by 1290%, 1160%, 690%, 1130%, 60%, 20%, and 200%, respectively, while aliphatic compounds such as 17, 18, 20, 22, 23, and 24 increased by 410%, 1410%, 3530%, 3530%, 2670%, 4140%, respectively.FIG. 6 identified intermediates found in ozonated column effluents collected by more frequent samplings. The gas chromatograms as shown focused on species with retention times of 40-50 min, which consisted mainly of pyrene, 2,2',6,6'-biphenyltetraaldehyde (2), 4,5-phenanthrenedialdehyde (3), and 1,2-benzenedicarboxylic acid, diisooctyl (4). In addition to these major species, spectrum (b) of FIG. 6 also identified long-chain aliphatic carbon compounds, including C21, C22, C23, C24, C25, and C26, shown as species 5 to 10, respectively. These long-chain hydrocarbons disappeared as the column effluent established steady-state levels of intermediates; henceforth only four major intermediates (1 to 4) remained after 45 min., as shown by chromatogram of FIG. 6(c). The presence of long-chain aliphatic hydrocarbons that have more carbons than the 16-C pyrene parent is suggestive of, during ozonation, the involvement of free-radical pathways in which radical recombinations are prevalent. The decomposing of O3 in water is known to occur through a series of free radical chain reactions that involve reactive radicals including OH./O.-, HO3./O3.-, and HO2./O2.. These reactive radicals are potent oxidants that can react with organic molecules leading to their mineralization.With identified intermediates and byproducts, in FIGS. 7a and 7b (the top of 7b continues from the bottom of 7a) is shown a proposed mechanism depicting the degradation pathway of pyrene under ozonation. As shown, the degradation was initiated by electrophilic attack of O3 on one of the electron-rich conjugate rings of the pyrene molecule resulting in the formation of dialdehyde (2) and, upon another ring-opening attack, tetraaldehyde (3). Pyrene has an asymmetrical fused-ring structure. The bonds between fused angular rings, as in 4,5- and 9,10-bonds (referred to as the K-regions), have the highest bond order (0.833) and shortest bond length (1.367) in the pyrene molecule (Harvey, 1997). These bonds show considerable double-bond character and are more reactive than other bonds, consistent with K-regions being the first activated reaction sites in metabolic oxidation. The preferential attack of O3 on the 4,5-bond of the pyrene molecule is also explained in terms of localization energy that marks the site as being most reactive (Bailey, 1982). Subsequent reactions of intermediates with O3 or oxygenated radicals (e.g., OH., O2.-, O3.-) resulted in additional intermediates (4)-(16). The production of long-chain aliphatic hydrocarbons, compounds (13) through (25), was attributed to oxidation reactions prompted by O3, OH., and other free radicals. With proposed intermediates and identified ones, FIGS. 7c and 7d details the formation and destruction of some of these compounds based on known reaction pathways reported in the literature. As shown, these reactions produced alkyl radicals that further propagated chain reactions and eventually led to polymerization via recombination of the organic radicals. Thus, the formation of many oxygenated intermediates (4, 7, 9, 12, 14, 16) as well as n-alkanes (19, 22) could be accounted for by FIGS. 7c and 7d. Another observation supporting the involvement of free radicals was the disappearance of these long-chain alkanes if the effluent was subject to prolonged ozone hydrolysis. Long-chain alkanes are characteristically resistant to electrophilic attack by O3 yet susceptive to OH. oxidation. Simpler short-chain polar aliphatic compounds were expected but not found in the reaction mixture; their absence was attributed to analytical extraction and preparation procedures that failed to retain compounds with less than six carbons. As O3 undergoes hydrolysis during ozonation, both O3 and OH. are available for the degradation of pyrene. It is plausible that the degradation pathway is initiated mainly via ring opening by O3, continued in fragmentation by both O3 and OH., and ultimately brought to complete mineralization primarily via OH. radicals.
  • 17
  • [ 1036648-35-7 ]
  • [ 629-97-0 ]
YieldReaction ConditionsOperation in experiment
63% Stage #1: docosyl 4-methylbenzoate With samarium diiodide In Norlaudanosolin Inert atmosphere; Reflux; Stage #2: With water; ammonium chloride In Norlaudanosolin Inert atmosphere;
63% With N,N,N,N,N,N-hexamethylphosphoric triamide; samarium diiodide In TETRAHYDROPYRANE Reflux; Inert atmosphere;
41% With tetrabutylammonium tetrafluoroborate at 130℃; Electrolysis;
  • 18
  • [ 112-95-8 ]
  • [ 629-97-0 ]
  • [ 630-01-3 ]
  • [ 629-50-5 ]
  • [ 593-45-3 ]
  • [ 646-31-1 ]
  • [ 630-02-4 ]
  • [ 638-68-6 ]
  • [ 112-92-5 ]
  • [ 629-96-9 ]
  • [ 593-50-0 ]
  • [ 661-19-8 ]
  • [ 506-51-4 ]
  • [ 506-52-5 ]
  • [ 557-61-9 ]
YieldReaction ConditionsOperation in experiment
1: 17.66% 2: 19.46% 3: 13.62% 4: 6.93% 5: 2.04% 6: 0.48% 7: 0.1% Stage #1: icosane; n-docosane; n-hexacosane; octadecane; tetracosane; octacosane; n-triacontane With oxygen at 30 - 50℃; for 0.5h; Stage #2: Tridecane With titanium(IV) isopropylate at 30 - 50℃; for 6.86667h; Stage #3: With sulfuric acid; water at 80℃;
  • 19
  • [ 124-18-5 ]
  • [ 629-62-9 ]
  • [ 112-95-8 ]
  • [ 629-97-0 ]
  • [ 629-50-5 ]
  • [ 629-59-4 ]
  • [ 544-76-3 ]
  • [ 629-78-7 ]
  • [ 593-45-3 ]
  • [ 629-92-5 ]
  • [ 629-94-7 ]
YieldReaction ConditionsOperation in experiment
With C22H41IrN2O2P2; Re2O7/Al2O3; 1,3,5-trimethyl-benzene at 175℃; for 168h; Inert atmosphere;
 

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