Ether, absolute

The zinc is purified by stirring 1.2 kg. of commercial zinc dust with 3 1. of 2% hydrochloric acid for 1 minute. The acid is removed by filtration, and the zinc is washed in a 4-1. beaker with one 3-1. portion of 2% hydrochloric acid, three 3-1. portions of distilled water, two 2-1. portions of 95% ethanol, and finally with one 2-1. portion of absolute ether, the wash solutions being removed each time by filtration. Then the material is thoroughly dried and any lumps are broken up in a mortar. 

A. Ester condensation. A suspension of 9.40 g. (0.41 gram atom) of powdered sodium in 100 ml. of absolute ether is placed in a 1-1. three-necked flask (Note 1) fitted with a reflux condenser, dropping funnel, and a calcium chloride tube. A solution of 23.8 ml. (0.41 mole) of absolute alcohol (Note 2) in 50 ml. of abso-... 

In a i-l. round-bottomed, three-necked flask fitted with an efficient reflux condenser, liquid-sealed stirrer, and dropping funnel is placed t3 g. (0.53 gram atom) of magnesium turnings. A few cubic centimeters of a solution of 60 g. (41.4 cc., 0.55 mole) of pure ethyl bromide in 50 cc. of absolute ether is added and the stirrer started (Note i). When the bromide begins to react 200 cc. of absolute ether is added, and then the balance of the bromide solution is run in as fast as the refluxing permits (about one-half hour). After allowing fifteen minutes for the completion of the reaction, a solution of 40 g. (0.42 mole) of 2,4-dimethyl-pyrrole (Org. Syn. 15, 20) in 100 cc. of absolute ether is added in the course of twenty minutes (Note 2) and the mixture is refluxed for one-half hour on the steam bath. 

After cooling to room temperature, a solution of 58 g. (51 cc., 0.53 mole) of freshly distilled ethyl chloroformate (b.p. 92.5-93.5°) in 160 cc. of absolute ether is added dropwise in the course of one-half hour (Note 3). The mixture is heated on the steam bath for one and one-half hours and then allowed to stand overnight at room temperature. 

In a 3-I. three-necked flask, fitted with a mechanical stirrer, a reflux condenser, and a separatory funnel, are placed 24.3 g. (i gram atom) of magnesium turnings, 500 cc. of absolute ether, a crystal of iodine, and a 5- to lo-cc. portion of 126.5 g- cc., I mole) of freshly distilled benzyl chloride (b.p. 177-179°). In a few minutes the reaction starts (Note 1) and is controlled if necessary by cooling with a wet towel. The stirrer is started and the balance of the benzyl chloride is run in as fast as the refluxing will permit. The addition requires from one to two hours, and when completed the mixture is refluxed ofi the steam bath with stirring for three hours. With the stirrer stUl running, 182 g. (r mole) of benzophenone (Org. Syn. Coll. Vol. i, 89) dissolved in 500 cc. of absolute ether is added at such a rate that the mixture refluxes rapidly. This requires about twenty minutes and then the reaction mixture is allowed to stand for two hours (Note 2). 

If an alcohol-free solution of diazomcthane is required, absolute ether should be used throughout this preparation. 

Zinc powder (32.8 g,0.5 moles) is washed successively with hydrochloric acid (3%, 4 X 25 ml), distilled water (4 x 30 ml), aqueous copper sulfate (2%, 2 X 50 ml), distilled water (4 x 30 ml), absolute ethanol (4 x 30 ml) and absolute ether (5 x 25 ml). The washings are performed conveniently by stirring a mixture of the zinc powder and each wash solution with a porcelain spatula in an open beaker and then decanting the supernatant liquid. The couple is finally transferred to a Buchner funnel, washed with additional anhydrous ether, and then vacuum-dried in a round-bottom flask. 

Hydroxy-B-homo-choIest-5-en-7a-one Acetate (67) A solution of 3p-hydroxycholest-5-en-7-one acetate (57 0.45 g) in absolute ether (140 ml) is placed in a 500 ml two-necked flask equipped with a mechanical stirrer and a calcium chloride drying tube. An ether solution of diazomethane (15.4 ml 0.42 g = 0.01 mole) is added with stirring at room temperature. Aluminum chloride (50 mg) is then added to the stirred solution. After 5 min an additional 50 mg of aluminum chloride is added. 

In 1896, Emil Fisher found that 2,5-diphenyloxazole hydrochloride was precipitated by passing gaseous hydrogen chloride into an absolute ether solution of benzaldehyde and benzaldehyde cyanohydrin. The oxazole hydrochloride can be converted to the free base by addition of water or by boiling with alcohol. Many different aromatic aldehydes and cyanohydrin combinations have been converted to 2,5-diaryloxazoles 4 by this procedure in 80% yield. ... 

By a more detailed study of the reaction of 5-azauracil with diazo-methane it was found that this reaction is considerably accelerated by the presence of a small amount of water, methanol, or dimethyl-formamide. It does not proceed appreciably in absolute ether. By... 

Zinc-Copper Couple A 500-ml Erlenmeyer flask equipped for magnetic stirring is charged with a mixture of zinc powder (49.2 g, 0.75 g-atom) and hydrochloric acid (40 ml of 3 % aqueous solution). The contents of the flask are rapidly stirred for 1 minute, and the liquid is decanted. Similarly, the zinc is washed with the following three times with 40 ml of 3% hydrochloric acid solution, five times with 100 ml of distilled water, five times with 75 ml of 2 % aqueous copper sulfate solution, five times with 100 ml of distilled water, four times with 100 ml of absolute ethanol, and five times with 100 ml of absolute ether. These last ethanol and ether washes are decanted onto a Buchner funnel to prevent loss. The residue is collected by suction filtration, washed again with anhydrous ether, and dried in air. Finally, the zinc-copper couple is stored (20-24 hours) in a vacuum desiccator over phosphorous pentoxide. 

WojQo 1-4652) in absolute ethereal solution was allowed to react with palladium black. After a few hours hydrogen was passed into the liquid at ordinary temperature, giving rise to a terpene possessing the following... 

On oxidation it yields veratric acid melting at 179° to 180°, and by the action of bromine on the phenol-ether dissolved in absolute ether, a dibromide is obtained, which melts at 101° to 102°. It has the constitution—... 

By precipitation of a solution of the ester in absolute ether with hydrogen chloride gas, the dihydrochloride is obtained upon recrystallization from alcohol/ether, it forms crystals which melt at 196°-197°C. 

A mixture consisting of 2 grams of 2-hydroxy-3-(N,N-diethylcarboxamido)-9,10-dimethoxy-1,2,3,4,6,7-hexahydro-1 Ib-H-benzopyridocoline (OH-axial) hydrochloride (prepared by treating the base with hydrogen chloride gas in absolute ether) dissolved in 7 ml of acetic anhydride containing 3 ml of pyridine was heated at 100°C for 2 hours under a nitrogen atmosphere. At the end of this period, a crystalline precipitate had formed and the resultant mixture was subsequently diluted with an equal volume of diethyl ether and filtered. 

A Grignard solution is prepared by introducing methyl chloride into a boiling suspension of 36 g of magnesium in 1,000 cc of absolute ether until all the magnesium has reacted. 

The reaction mixture was poured into 25 ml of water and the mixture made strongly basic with ION sodium hydroxide solution. The mixture was extracted 3 times with 50 ml portions of benzene, the combined extracts washed with water and concentrated to a volume of approximately 50 ml. The solution was saturated with dry hydrogen chloride and the white crystalline product collected and dried. The yield of product, MP 251.6° to 252.6°C (dec.) was 2.5 g. Recrystallization from a mixture of absolute alcohol and absolute ether gave a product, MP 252.6° to 253.6°C. A sample was analyzed after drying for 7 hours at 110°C over phosphorus pentoxide in vacuo. 

A solution of 34 cc (0.5 mol) of liquid phosgene in 150 cc of absolute ether is reacted while cooling with a mixture of sodium chloride and ice, first with 62 grams (0.5 mol) of 1-ethinyl cyclohexanoM and then with 64 cc (0.5 mol) of quinoline. The precipitated quinoline chlorohydrate is filtered off and the filtrate is reacted with ammonia in ether. 

Preparation of 11 -Hydroxy-6a-Methylprogesterone A mixture of 2.68 g of 11-keto-6(3-methylprogesterone 3,20-bis-(ethylene ketal), 161 ml of tetrahydrofuran (previously distilled from lithium aluminum hydride), 1.34 g of lithium aluminum hydride and 14.5 ml of absolute ether was stirred and refluxed under nitrogen for 1.5 hours, then 27 ml of water was added cautiously, to decompose excess hydride. The resulting mixture was filtered and the filter cake was washed with 135 ml of ether. The combined filtrate and wash was shaken with 135 ml of water and separated. The aqueous layer was washed with four 55-ml portions of ether, then the organic layer and the washes were combined, washed once with water, and evaporated to dryness under diminished pressure leaving a tan residue. 

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