Teflon flask

The procedure for preparing the crystals of the CA-M adduct was as follows. Aqueous solutions of cyanuric acid (0.1 mmol) and melamine, (0.1 mmol) were mixed in a Teflon flask, and the mixture (15 mL) was kept in a stainless steel bomb. The bomb was sealed and maintained in a furnace at 180 °C. Rectangular platelike crystals of good quality separated from the solution, upon cooling the bomb to room temperature over a period of 4 h. These crystals were used for collecting intensity data on the single-crystal... 

Some years ago D. Stuerga designed a microwave reactor, called the RAMO (reac-teur autoclave microonde), which is not a commercial device. The microwave applicator and the reactor are original. The resonant frequency of the cavity can be controlled by varying the position of a plunger. The effective cavity power can be increased by three orders of magnitude. The autoclave is made of polymeric materials, which are microwave transparent, chemically inert, and sufficiently strong to accommodate the pressures induced. The reactants are placed in a Teflon flask inserted within a polyetherimide flask. A fiber-optic thermometry system, a pressure transducer, and a manometer enable simultaneous measurement of temperature and pressure within the reactor. The system is controlled by pressure. The reactor is shown in Fig. 2.32. 

The Michael addition of secondary amines to a,)S-unsaturated carbonyl compounds under MWI essentially required the presence of water to drive the amine addition to completion and the presence of at least 10 mole equivalents of the amine. Besides increasing the polarity and possibly some micellar effect, water facilitates protonation of the resulted enolate from amine addition. In a typical procedure, benzalacetophenone was mixed with morpholine (469) and water in a teflon flask and subjected to MWI for 2 min to yield 93% of the 1,4-adduct 471 (Scheme 92). The method was also extended to other morpholine derivatives 472 and 473 in 30% and 100% yields, respectively (00SC643). 

A dry 1-L, three-necked, round-bottomed flask equipped with a large Teflon-covered magnetic stirring bar, a thermometer, and a dry ice condenser (Note 1) is flushed with argon (Note 2), then capped with a serun stopper and subsequently maintained under a positive pressure of argon (Note 3). A 30 dispersion of lithium metal (in mineral oil) containing 1% sodium (13.9 g, 2.00 g-atom of lithium) (Note 4) is rapidly weighed and transferred to the flask. 

The apparatus consists of a 1-1. three-necked flask equipped with a condenser, a dropping funnel, and a stirrer terminating in a stiff, crescent-shaped Teflon polytetrafluoroethylene paddle. The stirrer motor must have good torque (Note 1). The assembled apparatus, which is protected from moisture by means of drying tubes in the condenser and funnel, is preferably predried. About 216-224 g. (1.62-1.68 moles) of powdered anhydrous aluminum chloride is added to the apparatus with as little exposure to the moisture of the air as possible (Note 2). While... 

After drying under vacuum this iodo azide (2.43 g) is suspended in 50 ml of ether and added with stirring to a cold (0°) slurry of lithium aluminum hydride (1.2 g) in 70 ml of anhydrous ether in a 250 ml 3-necked flask (fitted with a reflux condenser and a mechanical stirrer with a Teflon blade). The remaining traces of the iodo azide are rinsed into the reaction flask with three 10 ml portions of ether. The reaction mixture is allowed to warm to room temperature and to stir for a total period of 11 hr. 

In a 250-ml. round-bottomed flask fitted with a glass-link or Teflon stirrer, thermometer, reflux condenser with outlet to an... 

A. (E)-l-Propenyllithium. A dry (Note 2), 500-ml., three-necked, round-bottomed flask equipped with a Teflon -covered magnetic stirring bar, a 200-ml. pressure-equalizing dropping funnel, an efficient reflux condenser, and an immersion thermometer is capped with serum stoppers (Note 3) and flushed with argon (Note 4). Lithium dispersion (Note 5), [22.4 g. of a 50% wjw suspension in Amseo,... 

Pure (A)-1 -chloropropene was obtained by careful distillation of a mixture of (E)- and ( )-l -chloropropene (available from Columbia Organic Chemicals Company Inc.) using a Nester-Faust Teflon annular spinning band column [(Z)-l-chloropropene has b.p. 33° (A)-l-chloropropene has b.p. 37°]. Small quantities of powdered sodium bicarbonate and hydroquinone (1,4-benzenediol) placed in the distillation flask inhibit acid-catalyzed isomerization and polymerization. Gas chromatographic analysis of the material used in these experiments on a 4-m., 15% l,2,3-tris(2-cyanoethoxy)propane (TCEP) on Chromosorb P column, operated at room temperature, typically indicated that it had isomeric purity >99.9%. (A)- 1-Chloropropene is stable for several months at room temperature, but it should be stored in a cool place. 

Today, the glassware required consists of either a round-bottom flask or a Schlenk tube serving as the reaction chamber. This chamber is equipped with a magnetic stirbar and a Teflon high-vacuum valve (or glass stopcock) which provides for easy vacuum control after attachment to a vacuum line (Fig. 8.7). 

The following steps are performed in an argon atmosphere glovebox. In a 50-mL round-bottom flask equipped with a Teflon magnetic stirbar, 2.03 g (14.7 mmol) of previously distilled and degassed 1,9-decadiene (9) (Aldrich) and 27.6 mg (3.61 x 10 2 mmol) of Schrock s catalyst (14) (400 1) are combined. In a matter of seconds, the catalyst is dissolved into the monomer and a vigorous evolution of ethylene is observed. The flask is sealed with a Teflon vacuum adapter and removed from the box. The polymerization vessel is immediately connected to the vacuum line, placed into an oil bath, and stirred at 30°C. Intermittent vacuum... 

To a mixture of 1,3-dibromobenzene (4.36 g, 18.49 mmol), 1,3-phenylene diamine 111 (2.00 g, 18.49 mmol), NaO-t-Bu (3.73 g, 38.84 mmol), Pd2(dba)3 (0.339 g, 0.37 mmol), and BINAP (0.691 g, 1.11 mmol) in a heavy-walled flask equipped with a Teflon valve was added THF (15 mL) under inert atmosphere. The flask was sealed and heated to 90°C. After 24 h, die reaction mixture was cooled to room temperature and neutralized using 0.2 mol equivalents of 2.4 N HC1 in MeOH. The polymer was precipitated from hexanes, filtered, and dried under vacuum. The dried polymer was redissolved in THF, filtered through Celite, and reprecipitated. The solid was collected by filtration and dien purified by Soxlilet extraction with CH2C12 overnight. After drying under vacuum, a green-tan solid was obtain in 106% yield. GPC (NMP, polystyrene standards) Mw = 39,000 ... 

B. 4-Nonylbenzoic acid. A 500-mL, round-bottomed flask equipped with a Teflon-coated magnetic stirbar and a reflux condenser is charged with 4-nonylbenzoic acid methyl ester (10.07 g, 38.37 mmol), 100 mL of methanol (Note 1), and 96 mL of 1M aqueous NaOH. The resulting mixture is heated at reflux for 18 hr and then allowed to cool to room temperature. The reaction mixture is carefully acidified by addition of 200 mL of 1M aqueous HC1, and the resulting solution is transferred to a separatory funnel and extracted with four 250-mL portions of ethyl acetate. The combined organic layers are dried over Na2S04, filtered, and concentrated by rotary evaporation at reduced pressure. The residue (ca. 9.5 g) is recrystallized from 70 mL of hexanes to give 8.32-8.35 g (87-88%) of 4-nonylbenzoic acid as a white solid (Notes 6, 7). 

B. (E)-4-(2-Phenylethenyl)benzonitrile (2). An oven-dried, 250-mL, three-necked, round-bottomed flask equipped with an argon inlet adapter, rubber septum, glass stopper, and a teflon-coated magnetic stir bar is cooled to room temperature under a flow of argon. The flask is charged successively with bis (tri-tert-butylphosphinc)palladium [(Pd(P(t-Bu)3)2] (0.238 g, 0.466 mmol, 1.5 mol% Pd) (Notes 1, 2), tris(dibenzylideneacetone)dipalladium(0) (Pd2(dba)3) (0.213 g, 0.233 mmol, 1.5 mol% Pd) (Note 3), and... 

All reagents were purchased from Aldrich Chemical Company (except for trimethylacetyl chloride, which the checkers obtained from Acros) and were used without further purification. The checkers used a low temperature alcohol thermometer in place of a Teflon-coated themocouple. The third neck of the flask was left open to the atmosphere. 

Irradiation Procedure. Reaction mixtures were prepared at room temperature by transferring desired quantities of reactants from their storage bulbs to the reaction vessel, a 500-cc. spherical borosilicate glass flask attached to the vacuum line by a section of glass capillary tubing and a 4-mm. bore threaded glass valve with a Teflon plug (Fischer and Porter 795-609). Prior to each experiment this vessel was baked under vacuum at 500°C. for 12 or more hours. 

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