72. The colouring matters of Drosera Whittakeri. Part III. The synthesis of hydroxydroserone

Winzor, F. L.

doi:10.1039/jr9350000336

Cited by 11 publications

(6 citation statements)

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“…Traces B and C show reference spectra of methyl-1,4-benzoquinone and 6-methyl-2-nitrophenol, respectively. The latter was not commercially available and it was synthesized using the method of Winzor . Similar product spectra are given in SI for the reactions of NO 3 with meta - and para -cresol (SI Figures SI-1 and SI-2, respectively).…”

Section: Resultsmentioning

confidence: 99%

FT-IR Product Study of the Reactions of NO₃Radicals Withortho-,meta-, andpara-Cresol

Olariu

Barnes

Bejan

et al. 2013

Environ. Sci. Technol.

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Product analyses of the NO3 radical-initiated oxidation of ortho-, meta-, and para-cresol have been performed in large-volume chamber systems at the University of Wuppertal (1080 L quartz glass reactor: QUAREC) and the European Photoreactor (EUPHORE), Valencia, Spain. The reaction of O3 with NO2 was used for the in situ generation of NO3 radicals in both QUAREC and EUPHORE. In the QUAREC experiments the gas-phase reaction of ortho-cresol isomer with NO3 yielded (11.5 ± 0.8) % 6-methyl-2-nitrophenol (6M2NP), (4.4 ± 0.3) % methyl-1,4-benzoquinone (MQUIN) and (77.2 ± 6.3) % HNO3. The reaction of NO3 radicals with meta-cresol yielded (21.2 ± 1.4) % 3-methyl-2-nitrophenol (3M2NP), (22.8 ± 1.8) % 3-methyl-4-nitrophenol (3M4NP), (23.5 ± 1.8) % 5-methyl-2-nitrophenol (5M2NP), (4.2 ± 0.7) % MQUIN and (72.3 ± 6.4) % HNO3. In the reaction of NO3 radicals with para-cresol, 4-methyl-2-nitrophenol (4M2NP) and HNO3 were identified as products with yields of (41.3 ± 3.7) % and (85.0 ± 10.2) %, respectively. In the EUPHORE chamber not all products were formed at levels above the detection limit, however, in cases where detection was possible similar product yields were observed. The product formation yields determined in both chambers are compared with available literature data and a gas-phase mechanism is proposed to explain the formation of the products observed from the reaction of NO3 and with cresol isomers.

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Section: Resultsmentioning

confidence: 99%

FT-IR Product Study of the Reactions of NO₃Radicals Withortho-,meta-, andpara-Cresol

Olariu

Barnes

Bejan

et al. 2013

Environ. Sci. Technol.

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“…The compounds used in this study, their manufacturer, and the manufacturer stated purity were: MB (Acros, 99%); MMB (Acros, 99%); 2-MP (Aldrich, 99%); 3-MP (Alpha Aesar, 97%); 2-M-4-MP (Alpha Aesar, 98%); 2,3-DMP (Aldrich, 99%); 2,6-DMP (Aldrich, 99%); 2-methyl-2-butene (Messer Griesheim, 99%); 1,3-butadiene (Messer Griesheim, 99%); propene (Messer Griesheim, 99.95%); 1-butene (Messer Griesheim, 99%); NO (Messer Griesheim, 99%); and synthetic air (Air Liquide, 99.999%). Methyl nitrite (CH 3 ONO) was prepared using a method described by Winzor and has been used with success previously as precursor for OH radicals in the OH-radical mediated oxidation of more complicated aromatic systems. , …”

Section: Methodsmentioning

confidence: 99%

Rate Coefficients for the Gas-Phase Reactions of Hydroxyl Radicals with a Series of Methoxylated Aromatic Compounds

et al. 2015

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Rate coefficients for the reactions of hydroxyl radicals (OH) with a series of oxygenated aromatics (two methoxybenzene and five methoxyphenol isomers) have been obtained using the relative kinetic method in 1080 and 480 L photoreactors at the University of Wuppertal, Germany. The experiments were realized at 295 ± 2 K and 1 bar total pressure of synthetic air using in situ Fourier transform infrared spectroscopy for the chemical analysis. The following rate coefficients (in units of cm(3) molecule(-1) s(-1)) were determined: methoxybenzene (anisole), (2.08 ± 0.21) × 10(-11); 1-methoxy-2-methylbenzene, (4.56 ± 0.50) × 10(-11); 2-methoxyphenol (guaiacol), (5.40 ± 0.72) × 10(-11); 3-methoxyphenol, (6.93 ± 0.67) × 10(-11); 4-methoxyphenol, (5.66 ± 0.55) × 10(-11); 2-methoxy-4-methylphenol, (7.51 ± 0.68) × 10(-11); 2,3-dimethoxyphenol, (7.49 ± 0.81) × 10(-11); and 2,6-dimethoxyphenol (syringol), (8.10 ± 0.98) × 10(-11). The rate coefficients for the reactions of OH with 2,3-dimethoxyphenol and 1-methoxy-2-methylbenzene are first time measurements. The rate coefficients determined in this work are compared with previous determinations reported in the literature and also with the values estimated using a structure-activity relationship method. A comparison is performed between the OH rate coefficients obtained for methoxylated aromatics with those of other substituted aromatics in order to understand the influence of the type, number, and position of the different substituents on the reactivity of aromatics toward OH. In addition, a comparison is made between the OH and Cl rate coefficients for the compounds. The principal atmospheric sink of these methoxylated aromatic compounds during daytime is their reaction with OH radicals. The corresponding lifetimes for reaction with OH radicals and Cl atoms are 2-8 and 11-50 h, respectively.

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“…6-Methyl-2-nitrophenol was prepared by addition of sodium nitrite to o-toluidine dissolved in a concentrated solution of sulfuric acid following a method described by Winzor. 33…”

Section: Methodsmentioning

confidence: 99%

Investigations on the gas-phase photolysis and OH radical kinetics of methyl-2-nitrophenols

Bejan

Barnes

Olariu

et al. 2007

Phys. Chem. Chem. Phys.

100

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Methyl-2-nitrophenols can be emitted directly to the atmosphere or can be formed in situ via the oxidation of aromatic hydrocarbons. Nitrophenols possess phytotoxic properties and recent studies indicate their photooxidation is effective in producing secondary organic aerosols. Therefore, investigations on the major photooxidation pathways of these compounds with respect to assessing their environmental impacts and effects on human health are highly relevant. Presented here are determinations of the rate coefficients for the reactions of OH radicals with four methyl-2-nitrophenol isomers using a relative kinetic technique. The experiments were performed in a 1080 l photoreactor at (760 +/- 10) Torr total pressure of synthetic air at (296 +/- 3) K. The following rate coefficients (in units of cm(3) molecule(-1) s(-1)) have been obtained: 3-methyl-2-nitrophenol, (3.69 +/- 0.70) x 10(-12); 4-methyl-2-nitrophenol, (3.59 +/- 1.17) x 10(-12); 5-methyl-2-nitrophenol, (6.72 +/- 2.14) x 10(-12); 6-methyl-2-nitrophenol, (2.70 +/- 0.57) x 10(-12). Photolysis of the methyl-2-nitrophenols with the superactinic fluorescent lamps (320 < lambda < 480 nm, lambda(max) = 360 nm) used in the experiments was observed. Photolysis frequencies measured for the methyl-2-nitrophenols in the photoreactor have been determined and scaled to atmospheric conditions. The results suggest that photolysis rather than the reaction with OH radicals will be the dominant gas phase atmospheric loss process for methyl-2-nitrophenols.

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72. The colouring matters of Drosera Whittakeri. Part III. The synthesis of hydroxydroserone

Cited by 11 publications

References 0 publications

FT-IR Product Study of the Reactions of NO₃Radicals Withortho-,meta-, andpara-Cresol

FT-IR Product Study of the Reactions of NO₃Radicals Withortho-,meta-, andpara-Cresol

Rate Coefficients for the Gas-Phase Reactions of Hydroxyl Radicals with a Series of Methoxylated Aromatic Compounds

Investigations on the gas-phase photolysis and OH radical kinetics of methyl-2-nitrophenols

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72. The colouring matters of Drosera Whittakeri. Part III. The synthesis of hydroxydroserone

Cited by 11 publications

References 0 publications

FT-IR Product Study of the Reactions of NO3Radicals Withortho-,meta-, andpara-Cresol

FT-IR Product Study of the Reactions of NO3Radicals Withortho-,meta-, andpara-Cresol

Rate Coefficients for the Gas-Phase Reactions of Hydroxyl Radicals with a Series of Methoxylated Aromatic Compounds

Investigations on the gas-phase photolysis and OH radical kinetics of methyl-2-nitrophenols

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FT-IR Product Study of the Reactions of NO₃Radicals Withortho-,meta-, andpara-Cresol

FT-IR Product Study of the Reactions of NO₃Radicals Withortho-,meta-, andpara-Cresol