Round bottom flask support

Flask F is provided with a two-hole cork stopper connected with tube E, and with tube G which connects with the first condenser II and may be of smaller bore than tubes C and E. H is. a. condenser with a 30-cm. water jacket. H is connected with I by means of an adapter. / is a i-l. round-bottom flask supported in a pan which is at first filled with ice and later used as a water bath. Flask I is fitted with a two-hole cork stopper carrying the adapter connected with condenser H and a Vigreux column K of 2-cm. diameter and a length of 30 cm. to the side arm. Flask I and condenser H are covered with black cloth (Note 2). The side arm of K is connected with a 90-cm. water-jacketed condenser L which leads into M through an adapter, iff is a 750-cc. Erlen-meyer flask immersed in an ice bath. Flask M is provided with a two-hole stopper connected with the adapter from L and an upright bulb condenser that is provided with a tube leading through a window or to a hood. 

Two convenient forms of bath are shown ui Fig. 11,10, 2, a and 6. The former consists of a long-necked, round-bottomed flask (a longnecked Kjeldahl flask of 100 ml. capacity is quite satisfactory) supported by means of a clamp near the upper part of the neck. The thermometer is fltted through a cork, a section of the cork being cut away (see inset) so that the thermometer scale is visible and also to allow free expansion of the air in the apparatus. The bulb is about three-quarters filled with... 

Place 50 g. (57 ml.) of dry A.R. benzene and 0 5 ml. of dry p rridine (1) (dried over potassium hydroxide pellets) in a 500 ml. round-bottomed flask. Attach a reflux condenser to the flask and an inverted funnel (just dipping into some water in a beaker) to the top of the condenser (Fig. II, 13, 8, b). Partially immerse the flask in a bath of cold water, supported upon a tripod and gauze. Carefully pour 125 g, (40 ml.) of bromine (for precautions to be taken with bromine, see Section 111,35, Note 1) through a condenser and immediately insert the absorption device into the upper end of the condenser. A vigorous reaction soon occurs and hydrogen bromide is evolved which is absorbed by the water in the beaker when the reaction slackens, warm the bath to 25-30° for... 

While the diazotisation is in progress, cautiously add 165 ml. of concentrated sulphuric acid to 150 ml. of water in a 1-litre round-bottomed flask. Heat the mixture just to boiling. Add the supernatant Uquid (diazonium solution) from a separatory funnel supported over the flask at such a rate that the mixture boils very vigorously (about 30 minutes). Then add the residual damp soUd (or suspension) in small portions avoid excessive frothing. When aU the diazonium salt has been introduced, boil for a further 5 minutes and pour the mixture into a 1-Utre beaker... 

A mixture of m-xylene (2,4 g, 22.6 nunol), alumina-supported copper(II) bromide (50.5 g), and carbon tetrachloride (60 ml) was placed in a 100 ml round-bottom flask and stirred with a Teflon-coated magnetic stirring bar at 80°C for 1 h. 

A mixture of fluorene (1.5 g, 9 mmol), alumina-supported copper(II) bromide (30 g), and carbon tetrachloride (80 ml) was placed in a 200 ml round-bottomed flask and stirred with a Teflon-coated magnetic stirring bar at 80°C for 5 h. The product mixture was filtered, and the spent reagent was washed with carbon tetrachloride (30 ml). Evaporation of solvent from the combined filtrate under reduced pressure yielded 2.84 g (97 %) of 2.7-dibromofluorene as a pale yellow solid having iH NMR and IR spectra identical with those of an authentic sample, mp 157-159°C (lit. mp 162-163°C (ref. 17)). The purity was > 96 % (GC). 

Transfer the residue prepared as in Section 6.1.1 into a 300-nL separatory funnel with 25 mL of phosphate buffer solution (0.1 M, pH 7.4). Add 10 mL of saturated aqueous sodium chloride and 50 mL of 0.5 M sodium hydrogen carbonate to the funnel and shake the funnel vigorously for 1 min. Add 70 mL of ethyl acetate to wash the aqueous layer to the funnel, shake, separate, and discard the ethyl acetate layer. Repeat this extraction procedure three times. Add 2 mL of phosphoric acid and 20 mL of an acetate buffer solution (0.1 M, pH 4) to the aqueous layer and extract the mixmre with 50 mL of ethyl acetate three times. Combine the extracts and filter into a 500-mL round-bottom flask through 60 g of anhydrous sodium sulfate supported by a plug of cotton wool in a funnel. Concentrate the filtrate to dryness under reduced pressure. 

Transfer the filtrate from Section 6.1.1 or 6.1.2 to a 500-mL separatory funnel and add 150 mL of 5% aqueous sodium chloride solution. Rinse the filter flask from the extraction procedure with two 40-mL portions of dichloromethane. Add both 40-mL rinses to the separatory funnel. Partition the residue into the dichloromethane. Filter the dichloromethane extract through a 10-cm filter funnel containing ca 50 g of anhydrous sodium sulfate supported on a plug of glass wool. Collect the dichloromethane in a 500-mL round-bottom flask. Repeat the partition and filtration steps with an additional 60 mL of dichloromethane. Rinse the sodium sulfate filter cake with 20 mL of dichloromethane and combine the partition and rinse solvents. Concentrate the combined dichloromethane solvents to dryness in a rotary evaporator under reduced pressure at <40 °C. 

Solution Activation 50 mg of supported Pt20 DEN was mixed with a solvent/acid mixture (see Table 1) in a 50 ml round bottom flask and refluxed for 2 - 6 hrs. Solid samples were separated from solution by vacuum filtration and dried in vacuum oven at 50°C overnight. To prepare sample 6 (see Table 1), supported Pt20 DENs were mixed with HN03/H20 (volume pore volume of Si02) in a sample vial, heated to 70°C for 2hrs, and dried in a vacuum oven at 50°C overnight. 

Finally, another related study from the Sun laboratory concerned the synthesis of hydantoins utilizing acryloyl chloride to prepare a suitable polymer support [87]. All steps were carried out under reflux conditions in a dedicated microwave instrument utilizing 50-mL round-bottomed flasks. Identical reactions under classical thermal heating did not proceed in the same time period. 

Two hundred and five grams T1 mole) of a-phenylcinnamoni-trile,2 2250 ml. of methanol, and 750 ml. of ether are placed in a 5-1. round-bottomed flask fitted with a two-necked adapter supporting a 1-1. separatory funnel and reflux condenser. The a-phenylcinnamonitrile is dissolved by gentle heating, and the solution is heated under reflux. A solution of 274 g. (4 moles) of 95% potassium cyanide in 600 ml. of water (which has been preheated to 45°) is added rapidly from the separatory funnel (Note 1). A small amount of potassium cyanide precipitates. The solution is heated under reflux for 1 hour, after which a solution of 154 g. (2 moles) of ammonium acetate in 250 ml. of water is added rapidly from the separatory funnel (Note 2). 

Support of a-[Os(CO)3Cl2]2 and K2CO3 on silica 7.65 g of Si02 is added to a 500-mL two-necked round-bottomed flask, equipped with a magnetic... 

A. 2-Trimethylsilyloxy-l,3-butadiene (1). An oven-dried 500-ml., three-necked, round-bottomed flask is fitted with two oven-dried addition funnels, a glass stopper, and magnetic stirrer, and placed in a 80-90° oil bath. Under an inert atmosphere, methyl vinyl ketone (25.0 g., 0.357 mole) in 25 ml. of dimethylformamide and chlorotrimethylsilane (43.4 g., 0.400 mole) in 25 ml. of dimethylformamide are added over 30 minutes to a magnetically stirred solution of triethylamine (40.5 g., 0.400 mole) in 200 ml. of dimethylformamide (Note 1). The reaction gradually darkens from colorless to yellow or dark brown, and supports a white precipitate of triethylamine hydrochloride. The reaction is set up to run overnight, or ca. 14 hours. 

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