Quartz immersion well

The photochemical quartz immersion well was obtained from Ace Glass... 

Figure 1. A, Dewar flask B, sintered glass filter C, metal cooling coil D, water inlet E, water outlet F, reaction vessel < , quartz immersion well /f, pyrex filter /, lamp ...

Nonyl aldehyde (32.66 g, 0.23 mol) and furan (200 mL, 187.2 g, 2.75 mol) were mixed in a 250-mL photolysis flask equipped with a quartz immersion well containing a Vycor filter and a 450-W Hanovia Lamp. The system was kept at -20° C with an isopropyl alcohol bath cooled by a Cryocool Immersion Cooler (CClOO). Nitrogen was bubbled throughout the duration of the reaction, and the solution was stirred vigorously. Additional furan (150 mL, 140.4 g, 2.06 mol) was added during the course of the reaction. TLC analysis indicated completion of the reaction after 20 h. After evaporation of excess furan and NMR analysis of the resultant oil (48.70 g, ca. 100%) indicated the desired photoadduct had been formed, without contamination from unreacted nonyl aldehyde. 

Acridine-9-carbonitrile 10-oxide (la 3.00g, 13.6 mmol) in benzene (1.8 L) in a quartz immersion well was irradiated for 3 h with a Hanovia high-pressure 450-W Hg lamp equipped with a Pyrex filter. The resulting solution was evaporated under reduced pressure and the residue was extracted with pentane (3 x 50 mL). The combined extracts were evaporated under reduced pressure at 20 C to give orange crystals yield 1.8 g (60%) mp 105-109 C (Et20/pentane). 

While still slightly warm from the drying oven, the photolysis vessel with a water-jacketed quartz immersion well (Note 1) (section A of Figure 2) is charged with 500 ml. of anhydrous tetrahydrofuran (Note 2) and 10 ml. (8.05 g., 0.122 mole) of cyclopentadiene (Note 3). The solution is cooled in an ice bath and purged with dry nitrogen for 2 minutes. Then the vessel is sealed, the lamp inserted, and the solution irradiated at 0° for 30 minutes. During this period, sections B and C... 

The apparatus is dried in an oven at 140° overnight and cooled under nitrogen or argon prior to the irradiation. A Vycor filter sleeve and a 450-watt medium-pressure mercury lamp are placed in the immersion well. The Vycor filter, the quartz immersion well (catlog No. 19434), the 450-watt mercury lamp (catalog No. 679A36), and the requisite transformer are all available from Hanovia Lamp Division, Canrad-Hanovia Inc., 100 Chestnut Street, Newark, New Jersey 07105. 

C. tert-Butyl fi-(l-ethoxycyclopropyl)carbamate. A three-necked, cylindrical irradiation vessel is equipped with a magnetic stirring bar, a water-jacketed quartz immersion well, an inert gas inlet,... 

To a solution of the diene (1 -2 g) in anhyd Et20 (140 mL) was added CuOTf (1 -2 moI%). This homogeneous solution was irradiated under an atmosphere of N2 with a medium-pressure Hg lamp through a water-cooled quartz immersion well until disappearance of the starting diene (15 40 h). After completion of the reaction, the Et20 solution was poured into a mixture of crushed ice and 30% NH4OH (100 mL) and shaken well. The two layers were separated and the deep blue aqueous layer extracted with Et,0 (2 x 50 mL). The combined Et,0 extracts were washed with brine and dried (MgSO+). Et,() was removed by rotary evaporation and the residual oil distilled. 

Two 50-mL Pyrex tubes containing the complex (0.1 g) dissolved in toluene (10 mL) were placed in a large ice bath equidistant from a 450-W high-pressure Hg lamp contained in a quartz immersion well. One of the tubes was wrapped in aluminum foil and the tubes were irradiated for 8-10 h. The gases above the solution were analyzed by GC. 

A homogeneous solution of the tetraene ether 86 (1.28 g, 8.5 mmol) in 85 mL of THF (0.1 M) with 43 mg (0.17 mmol, 2mol%) of CuOTf was irradiated for five days under argon by using a quartz immersion well. Evaporation of the solvent gave a brown, oily residue which was purified by filtration over basic alumina to give a 2.5 1 mixture of 88 and 198 (63%) which were separated by HPLC. 

A. 3-(l-Hyivoxybutyl)-l-methyl-pyrvole (1). A photochemical quartz immersion well (220 mu length) (Note 1) equipped with 450-watt Hanovla medium pressure mercury lamp and a Vycor filter, cooled with water, 1s used. To a 125-mL Pyrex reaction vessel (230 mn long, 64 mm i.d.) equipped with a gas inlet and outlet, is added 60 rriL (55 g, 0.676 mol) of 1-methylpyrrole (Note 2)... 

Fig. 1. Reaction vessel, immersion well, and filtration assembly for the photochemical preparation of metal nitrosyls. A = Teflon needle stopcock, 0-5 mm B = O-ring connector, tube i.d. 75 mm F = fritted glass disk, o.d. 15 mm L = mercury lamp O = O-ring connector, tube i.d. 15 mm P = Pyrex tubing, o.d, 80 mm, length 10 in. Q = water-cooled quartz immersion well, o.d. 65 mm V = Viton O ring.

Irradiation was carried out with a Hanovia Model L mercury lamp in a quartz immersion well and a Coming uranium glass filter. 

A soln of 3,5-dimethoxybenzyloxycarbonyl-D-Phg-Gly-OH (1.00 g, 0.00249 mol) in dioxane/HjO (1 1, 1L) was irradiated with a Hanovia 654A-36 high-pressure Hg lamp housed in a water-cooled quartz immersion well fitted with a Vycor glass filter sleeve. After 1.5 h, the solvent was removed from the soln to dryness under reduced pressure and the residue treated with a minimal volume of acetone. Filtration afforded H-D-Phg-Gly-OH yield 0.335g (65%) mp 226-228 C [a] -112 (c, 0.484 in IM HCl). 

The irradiation light source is a Hanovia 450 W medium-pressure Hg vapour lamp placed in a quartz immersion well. The reaction solution is contained in a 150 ml quartz semicircular flask mounted as closely as possible to the immersion well. No light filter is used. The entire apparatus is immersed in a large Dewar flask charged with dry ice-isopropanol with the bath temperature maintained between —60 and —40°C during irradiation. 

Method 2. A convenient method for small scale preparations of these compounds uses Schlenk techniques. To a 100-mL quartz Schlenk tube is added 0.5 to 1.0 mL (38. to 76. mmol) of Fe(CO)s, 3 to 5 equivalents of phosphine, and 80 mL of dry deoxygenated cyclohexane. The Schlenk tube is placed adjacent to the mercury arc lamp contained in the quartz immersion well. The sidearm of the Schlenk flask is attached to N2 flushed Tygon tubing, which is connected to the bubbler and an inverted water-filled graduated cylinder (500 mL) contained in a partially filled beaker. 

A solution of 9-diazo-9f/-fluorene (200 mg, 1.0 mmol) in styrene (20 mL, 18.2 g, 0.17 mol) was placed in a Pyrex outer jacket surrounding a quartz immersion well. After being purged with a dry N2 gas stream for 2 h, the solution was irradiated for 24 h with a Hanovia 450-W medium-pressure Hg lamp placed within the water-cooled immersion well and shielded by a cylindrical uranium glass filter to remove all wavelengths below 330 nm. After removal of excess styrene in vacuo, yellow crystals were observed. Purification by chromatography on a column of silica gel (230-400 mesh) with 20% benzene in hexane as eluant gave 246 mg (92%) of product mp 127 C. 

A sample of (la,7a)-bicyclo[5.1.0]oct-2-en-4-one (300 mg, 2.46 mmol) was dissolved in pentane (20 mL) and the resulting solution was placed under N2 in a quartz test tube affixed to a quartz immersion well, which was equipped with a 200-W Hanovia Hg arc and Pyrex filter. The solution was irradiated for 2.5 h. The solvent was removed at reduced pressure at 0°C to afford 250 mg of a yellow oil which was purified by preparative VPC at 90 C yield 116 mg (39%). 

Small (1-5 g) scale UV photolysis of air sensitive compounds can be performed in quartz Schlenk tubes, or in conventional Schlenkware with the use of a UV transparent quartz stopper. The latter apparatus is easily adapted to low temperature irradiations. Large scale (10-50 g) UV photochemical reactions use quartz immersion well reactors. Medium pressure Hg-arc lamps are the preferred radiation sources for synthetic applications. ... 

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