Powder funnel

B. (l-Azido-3,3-dimethoxy-l-propenyl)benzene. In a 2-1., one-necked, round-bottomed flask equipped with a magnetic stirrer and powder funnel are placed 156 g. (0.45 mole) of the iodoazide from Part A and 1500 ml. of anhydrous ether. The solution is stirred and cooled in an ice-salt bath (— 5° to 0°), and 62 g. (0.55 mole) of potassium <-butoxide (Note 6) is added. The powder funnel is then replaced by a calcium chloride drying tube and the mixture is stirred for 4 5 hours at 0°. At the end of this time 350 ml. of water is added while the mixture is still cold. The ethereal layer is then separated and washed with three 350-ml. portions of water and dried over magnesium sulfate. The solvent is removed with a rotary evaporator without heating, leaving 67-75 g. (68-76%) of (l-azido-3,3-dimethoxy-l-propenyl)-benzene as a dark oily liquid (Note 7). This material can be used without further purification for Part C (Note 8). 

When solids are added to the flask, the gas outlet is replaced by a powder funnel and nitrogen flow is increased slightly. If a separatory funnel is used (cf. Note 10), a dual outlet is needed. 

If the chloropyruvic acid remains essentially as a viscous liquid, it may be introduced via a dropping funnel containing a large-bore stopcock. If the material has set up to a waxy solid, it must be introduced in portions through a powder funnel. 

A 500-ml, three-necked, round-bottom flask is fitted with a mechanical stirrer, a thermometer, and a wide-stern (powder) funnel. The flask is cooled in an ice-salt bath and charged with 125 ml (approx. 0.5 mole) of 15% sodium hydroxide solution. When the stirred solution reaches -10°, 30% hydrogen peroxide (57.5 g, 52.5 ml, approx. 0.5 mole) previously cooled to -10° is added in one portion. The pot temperature rises and is allowed to return to —10° whereupon 37.5 g (0.25 mole) of phthalic anhydride (pulverized) is added rapidly with vigorous stirring. Immediately upon dissolution of the anhydride, 125 ml (approx. 0.25 mole) of cooled (-10°) 20% sulfuric acid is added in one portion. (The time interval between dissolution of the anhydride and the addition of the cold sulfuric acid should be minimized.) The solution is filtered through Pyrex wool and extracted with ether (one 250-ml portion followed by three 125-ml portions). The combined ethereal extracts are washed three times with 75-ml portions of 40% aqueous ammonium sulfate and dried over 25 g of anhydrous sodium sulfate for 24 hours under refrigeration. 

In a 1-1. three-nccked, round-bottomed flask equipped with a mechanical stirrer, reflux condenser, and powder funnel are placed 180 ml. of reagent grade chloroform, 16.0 g. (0.16 mole) of cyclobutanecarboxylic acid (Note 1), and 48 ml. of concentrated sulfuric acid. The flask is heated in an oil bath to 45-50°, and 20.0 g. (0.31 mole) of sodium azide (Note 2) is added over a period of 1.5 hours (Note 3). After the addition of sodium azide is complete, the reaction mixture is heated at 50° for 1.5 hours. The flask is cooled in an ice bath, and approximately 200 g. of crushed ice is added slowly. A solution of 100 g. of sodium hydroxide in 200 ml. of water is prepared, cooled to room temperature, and then added slowly to the reaction mixture until the pH of the mixture is approximately 12—13. The mixture is poured into a 2-1. three-necked, round-bottomed flask, the... 

The sodium azide is added at such a rate that a gentle reflux of vapors in the powder funnel is maintained. After somewhat more than the theoretical amount of azide has been added, the rate of addition may be much more rapid. 

If the lithium borohydride sticks to the spatula or powder funnel, additional methanol can be used to wash the material into the reaction mixture without affecting the yield. On this reaction scale, an additional 25-50 mL of methanol could be used. Using 2.0M LiBH4 in THF instead of solid LiBH4 complicates the following step resulting in lower yields. 

A, trans-2,4-Pentatiienoic acid. A 1-1., three-necked, round-bottomed ilask is equipped with a mechanical stirrer, a condenser cooled with ice-cold water (Note 1) and bearing a calcium chloride drying tube, and a powder funnel. The flask is charged with 206 g. (210 ml., 2.6 moles) of pyridine (Note 2), vigorous stirring is... 

Explodes violently on heating above 240°C [1]. A I4g sample exploded while being transferred to a cold, empty, unagitated flask via a polythene powder funnel, injuring the worker. The isolated salt was essentially neutral, so excess periodic acid cannot be involved. Subsequent attempts to explode the material deliberately have failed, but it is felt that static electricity may be the cause [2], [3],... 

A. Oximinomalononitrile. Malononitrile (Note 1) (25 g., 0.38 mole) is dissolved in a mixture of 20 ml. of water and 100 ml. of acetic acid in a 1-1. round-bottomed flask equipped with a stirrer, a thermometer, and a powder funnel. The solution is cooled to —10° with a dry ice-acetone bath, and 50 g. (0.72 mole) of granulated sodium nitrite is added in approximately 2-g. portions over a 30-minute period while the temperature is maintained at 0° to —10°. After the addition is complete a wet ice bath is used to maintain the temperature below 5° while the mixture is stirred for 4 hours. Four hundred milliliters of tetrahydrofuran (Note 2) and 400 ml. of ether are added in separate portions, and the mixture is stored at —40° overnight. The mixture is filtered rapidly, and the solid is washed with a mixture of 200 ml. of tetrahydrofuran (Note 2) and 200 ml. of ether. The filtrate and washings are combined and concentrated by distillation to a volume of 250 ml. by the use of a water aspirator and a bath at 40° (Note 3). This solution of oximinomalononitrile is used directly in the next step. 

A. l-Phenyl-2,2,2-lrichloroethanol. In a 1-1. round-bottomed-flask fitted with a mechanical stirrer, a thermometer, and a powder funnel is placed a solution of 212 g. (2.00 moles) of freshly distilled benzaldehyde in 400 g. (270 ml., 3.35 moles) of chloroform. The mixture is cooled in an ice bath, and 123 g. of commercial powdered potassium hydroxide is added with stirring at such a rate that the temperature of the solution does not exceed 45° (1-1.5 hours). The reaction mixture is stirred and kept at 40-50° for an additional hour and then poured into a solution of 60 ml. of sulfuric acid in 3 1. of water. The resulting two-phase mixture is transferred to a separatory funnel and extracted with three 250-ml. portions of chloroform (a small amount of insoluble, black resinous material is discarded). The combined organic layers are washed with three 100-ml. portions of aqueous 10% sodium carbonate, dried over anhydrous magnesium sulfate, and filtered into a 1-1. flask. The solvent is removed under reduced pressure on a hot water bath. The residue is transferred to a 250-ml. flask and distilled under reduced pressure to give l-phenyl-2,2,2-trichloroethanol, b.p. 155-165° (26 mm.), 90-100° (0.5 mm.) (Notes 1 and 2). The yield is 170-180 g. (38-40%). 

In a 1-1. three-necked flask equipped with a dry ice-acctone condenser and a sealed mechanical stirrer is placed 700 ml. of commercial, anhydrous, liquid ammonia. To the stirred ammonia is added a small piece of potassium metal. (Caution1 Care should he exercised in handling potassium metal, since it is extremely reactive and it ignites on contact with water, atmospheric moisture, or alcohol. It should he manipulated under toluene or xylene, and blotted with filter paper before addition.) After the appearance of a blue color a few crystals of ferric nitrate hydrate (ca. 0.1 g.) are added, followed by small pieces of freshly cut potassium metal until 7.0 g. (0.18 g. atom) has been added. After all the potassium has been converted to the amide (Note 7), 24.9 g. (0.154 mole) of sodio-2-formyl-6-methylcyclohexanone is added carefully through a powder funnel (Note 8). After 1 hour a solution of 28.2 g. (0.21 mole) of w-butyl bromide (Note 9) in 50 ml. of anhydrous ether is added dropwise from an addition funnel. The mixture is stirred for 3 hours, and then the dry ice-acetone condenser is replaced by a water condenser. A steam bath is placed under the flask, and the ammonia is evaporated (Caution ) as 400 ml. of anhydrous ether is added. When the... 

A 2-1. three-necked flask is thoroughly dried and fitted with a large dry-ice condenser, a mechanical stirrer, a nitrogen inlet, and a powder funnel in an efficient hood. With nitrogen flowing through the system, 62.5 g. (1.60 moles) of commercial sodium amide (Note 1) is added rapidly. (Caution Sodium amide is corrosive and readily decomposes in the presence of moisture.) The funnel is replaced by a gas-inlet tube, the condenser is filled with a mixture of dry ice and acetone, and ca. 400 ml. of liquid... 

The guy at the next bench said it was only a two-dollar powder funnel and not to worry and the line at the stockroom was long anyway, and. . . and. . . anyway the stem was only cracked a little. . . and it worked O.K. all year long. . . Nobody said anything.. .. ... 

Toluenesulfonyl chloride (175 g, 0.918 mol) is added in one portion under an inert atmosphere via Gooch tubing (the checkers used a powder funnel for the addition). The temperature rises to 40°C for 15-20 min, but returns to 5°C where it is maintained for 2 hr. Twenty 1-mL portions of water are next introduced at such a rate that the temperature does not exceed 5°C. The... 

The jacketed addition funnel is removed and 1.5 g of cuprous bromide-dimethyl sulfide complex (Note 7) is added through a powder funnel. A 500-mL, pressure-equalizing addition funnel (long-tipped) is attached to the flask and flushed with argon. As the anion solution is cooled in a dry ice-isopropyl alcohol bath, a solution of 530 g (2.08 mol) of sublimed iodine in 500 mL of anhydrous tetrahydrofuran is placed in the addition funnel. This solution is added dropwise to the cooled slurry over approximately 90 min (Note 8). The solution is stirred for about 15 min at low temperature. 

B. Ethyl pyrrole-2-carboxylate. In a 1-1. three-necked round-bottomed flask equipped with a sealed mechanical stirrer and powder funnel are place 1.0 g. of sodium and 300 ml. of anhydrous ethanol. When the sodium is dissolved, 75 g. (0.35 mole) of pyrrol-2-yl trichloromethyl ketone from Part A is added portionwise over a 10-minute period (Note 4). After the addition is complete, the solution is stirred 30 minutes, then concentrated to dryness using a rotary evaporator. The oily residue is partitioned between 200 ml. of ether and 25 ml. of 3 N hydrochloric acid. The ether layer is separated, and the aqueous layer is washed once with 100 ml. of ether. The ether solutions are combined, washed once with 25 ml. of saturated sodium bicarbonate solution, dried with magnesium sulfate, and concentrated by distillation. The residue is fractionated at reduced pressure to give 44.0-44.5 g. (91-92%) of ethyl pyrrole-2 carboxylate as a pale yellow oil, b.p. 125-128° (25 mm.) (Note 5). The yield based on pyrrole is 70-74%. Upon standing at room temperature the product crystallizes, m.p. 40-42°. 

A. Methyl a-[(methoxyethylidene)amino]acetate (1). A flame-dried, 500-mL, twonecked, round-bottomed flask is equipped with a stir bar, rubber septum, eind an argon inlet. The flask is charged with methyl acetimidate hydrochloride (10.0 g, 91 mmol) (Note 1) and dry dichloromethane (140 mL) (Note 2). The stirred suspension is cooled to 0°C and solid methyl glycinate hydrochloride (11.5 g, 91 mmol, Note 1) is added in one portion with a powder funnel under a stream of Ar. After the mixture is stirred for 45 min at 0°C, a solution of dry triethylamine (12.7 mL, 91 mmol) (Note 2) in dry dichloromethane (11 mL) is added via syringe pump during 2.5 hr. Stirring is continued for 5 hr while the mixture is... 

Introduction of alkali metal into the flask containing liquid ammonia is most easily done with a powder funnel, which temporarily replaces a part of the equipment The cleaned lumps of metal are held above the funnel and cut into pieces (for handling alkali metals see our previous book "Preparative Polar Organometallic Chemistry , Springer-Verlag, 1987.)... 

Apparatus 3-1 round-bottomed, three-necked flask, equipped with a gas inlet tube, a mechanical stirrer and a powder funnel (fig. 15), the powder funnel is replaced by a vent as soon as the introduction of the metal is completed. 

Apparatus fig. 1,11 for the addition of the elements the dropping funnel is replaced with a powder funnel. 

The starting compound (0.50 mol, note 1) is added dropwise over 30 min to a solution of 2.2 mol of potassium amide [1,3,4] in 1.5 1 of liquid ammonia. After an additional 2 h the dropping funnel is replaced by a powder funnel and 100 g of powdered ammonium chloride is... 

Apparatus 1-1 three-necked, round-bottomed flask, equipped with a mechanical stirrer, a powder funnel and a thermometer. 

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