Pyrex vessel

The catalytic degradation of PS was carried out in a semi-batch reactor where nitrogen is continuously passed with a flow rate of 30 mL/min. A mixture of 3.0 g of PS and 0.3 g of the catalyst was loaded inside a Pyrex vessel of 30 mL and heated at a rate of 30 C/min up to the desired temperature. The distillate from the reactor was collected in a cold trap(-10 °C) over a period of 2 h. The degradation of the plastic gave off gases, liquids and residues. The residue means the carbonaceous compounds remaining in the reactor and deposited on the wall of the reactor. The condensed liquid samples were analyzed by a GC (HP6890) with a capillary column (HP-IMS). 

Tamaru et al.lz restudied this reaction by a static method using a cylindrical pyrex vessel (volume, 67 cm3 inside diameter, 2.7 cm) with an initial pressure of undiluted germane between 50 and 400 torr. The temperature range was 278-330°C. 

The reactions are normally performed at 100°C with 2 equiv of isonitrile (2,6-xylylisonitrile) in benzene in a Pyrex vessel with UV irradiation (250 W high-pressure Hg lamp). The reactions also work in the dark, but a higher temperature and larger reaction times are required. 

Gilberto Zorio made a series of works using Pyrex vessels. These containers engage the viewer in a dialectic between heaviness and lightness, transparency and the liquidity of the glass, and alcohol that eventually... 

Similarly irradiation in diethyl ether (Pyrex vessel, 3000-A lamp, 2 h) of bicyclo[2.2.2]oct-5-en-2-one gave bicyclo[4.2.0]oct-2-en-8-one (6 a) in 13% yield by 1,3-acyl shift.61... 

Irradiation of thioglycolic acid and of dimethyl dithiodiglycollate in the presence of 3,4-benzpyrene (LII) with a mercury arc in quartz vessel, but not in a Pyrex vessel, produces 5-benzpyrenylacetic acid (LIII) and methyl 5-benzpyrenylacetate, respectively. The latter is also obtained on irradiation of 5-benzpyrenylmercaptoacetic acid (LIV).48... 

Terao and Shida130 have reported that CH2 from ketene photolysis in a quartz or Pyrex vessel reacted with benzene to give cycloheptatriene and toluene in the ratio 2.3 1, with evidence of at least one other unidentified product. The product ratio was independent of pressure in the range 16-1000 mm., including 4r-60 mm. CH2CO, 12-60 mm. C6H6, and added N2 or C02. 

With toluene, in a Pyrex vessel, the products were ethylbenzene, m-and p-xylenes, and an unidentified product. In a quartz vessel o-xylene was also found and the unidentified product decreased, suggesting that the unidentified product was a methyl cycloheptatriene capable of undergoing photoisomerization to give xylenes. 

A 1-L Pyrex vessel is charged with 29.5 g (0.13 mol) of (5S)-(5-0-tert-butyldimethylsiloxymethyl)furan-2(5H)-one, 23.7 g (0.13 mol) of benzophenone (Note 10) and 800 mL of methanol. The vessel is placed in a water-cooled, immersion-irradiation apparatus (Note 11), and the solution is degassed for 1 hr in a stream of nitrogen. It is then irradiated using two 125-watt, 350-nm lamps the reaction is complete after 48 hr (Note 12). The solvent is evaporated and the residue is purified by silica chromatography [1 kg of silica, 8.5-cm x 43-cm column with a gradient elution from ethyl acetate petroleum ether (1 1) to neat ethyl acetate]. This yields 18.5 g (55%) of the title compound, 18.3 g (77%) of recovered benzophenone, 3.6 g of benzpinacol,... 

The reaction was studied at nitric oxide and hydrogen iodide pressures of 40-500 and 120-750 torr, respectively. The reaction rate was determined by analyzing for NO and I2 at various times and, in some cases, for ammonium iodide and hydrogen iodide. In clean Pyrex vessels results were not reproducible, but in vessels seasoned with a carbonaceous deposit reproducibility was satisfactory and the reaction was observed to be homogeneous. The rate law was determined to be second order... 

Irradiation of troponoid systems leads to a variety of photochemical reactions which include valence tautomerization, deep-seated rearrangement and dimerization. The photochemical transformations of troponoid systems as a general rule proceed readily in Pyrex vessels and thus must involve excitation of the intense, long wavelength absorption band (320-350 m/t) of the troponoid system. 

Irradiation of 1,2-diketones of appropriate structure gives remarkably high yields of 2-hydroxycyclobutanone derivatives. Exposure of 5,6-decanedione to sunlight for twelve hours in a Pyrex vessel gives 11% unreaCted dione and 89% 2-butyl-3-ethyl-2-hydroxycyclobutanone (Formula 260) (110). 

A suitable quantity of material for the preparation in a Pyrex vessel is about 250-mm. pressure of each gas. 

All reactions were performed in a cylindrical Pyrex vessel using 10 mmol of nitrone 1 and 20 mmol of dipolarophiles 2 or 4. The mixtures were introduced into the monomode reactor (Maxidigest MX 350 Prolabo) at the powers and times indicated in Table 1. Temperatures were recorded throughout the reaction using an IR detector connected to the reactor. At the end of the reaction, after cooling down and extraction with CH2CI2, products 3, 5a and 5b were analyzed by GC methods using an internal standard and authentic samples. 

Liquid 1 (0.50 g, 2.6 mmol) was crystallized in an evacuated 500-mL flask at -45 °C. Methanethiol at a pressure of 0.3 bar was let in and illumination was performed through the cooling bath out of methanol in a Pyrex vessel using a high-pressure Hg-lamp (Hanau, 150 W) for 5 h. Product 2 was isolated as an oil by preparative TLC. There was no addition in the absence of light. 

Ikeda et al. [80] have reported a photochemical entry to spiro-(3-lactams 27 (Scheme 8) by the irradiation of a solution of 2 - (/V - ac y I - /V-al k y I a m i n o) eye I o h e x -2-enone 26 in acetone with a 300 W high pressure mercury lamp in a pyrex vessel under nitrogen. The reaction occurred with the intervention of the 1,4-diradical intermediate formed via abstraction of a hydrogen on the N-acyl group by the (3-carbon atom of the ot,(3-enone system. 

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