Ethanol, absolute, preparation continuous

The 1.5 M solution of dimethylamine in ethanol was prepared as follows Aqueous 40% dimethylamine is heated at 65°C under a flow of argon. The gas is passed through potassium hydroxide pellets and blown across a known quantity (100 mL) of absolute ethanol (analytical grade used without purification), then cooled to 0°C in an ice bath, with continuous stirring, for 3 hr. The ethanolic solution is weighed and diluted to 150 ml with absolute alcohol. The ethanolic dimethylamine solution (ca. 1.5... 

E. Quench and purification. While the butyllithium addition is taking place, an acidic ethanol quench solution is prepared in a 3-L, two-necked, round-bottomed flask, equipped with a mechanical stirrer and a 250-mL, pressure-equalizing dropping funnel. The flask is charged with 1 L of absolute ethanol and the funnel with 250 mL of acetyl chloride. The ethanol is stirred rapidly and the flask is cooled with an ice bath as the acetyl chloride is added over a 30-40-min period and then the cooling bath is removed and stirring is continued for 20-30 min. After the main reaction mixture has been stirred for 30 min at room temperature, it is cooled with a dry ice-acetone bath. The acidic ethanol solution is cooled with an ice bath and the cold, main reaction mixture is quenched by addition (via a double-ended needle) into the rapidly stirred, cold, acidic ethanol solution over a 3 to 3.5 hr period (Note 16). 

Preparation of nitrile acetates from oximes with sodium acetate and acetic anhydride. Pentaacetyl-v-glucononitrile. If only the nitrile is needed, isolation of the oxime can be avoided. One hundred grams of anhydijous n-glucose was dissolved in 50 ml. of warm water, and maintaining the temperature at 60°, a solution of 28 g. of hydro-xylamine in 700 ml. of ethanol was added sufficiently slowly that no precipitation took place. After one hour at 65°, the reaction mixture was concentrated under reduced pressure to a thick sirup. The residue was mixed with absolute ethanol, the ethanol evaporated and the operation repeated in order to eliminate all water. One hundred and twenty grams of anhydrous sodium acetate and 700 ml. of acetic anhydride were added to the sirup, and the mixture was slowly and cautiously warmed in a water bath to 95°. It was advisable to agitate the flask continuously and to watch the... 

In an apparatus similar to the one described in Preparation 3-1, a mixture of 10 gm (0.041 mole) of 2,2 -dinitrobiphenyl, 133.4 ml of absolute ethanol, and 13.4 ml of aqueous solution containing 10 gm of sodium hydroxide is warmed, with stirring, on a water bath to 70°-80°C. At that temperature 30 gm (0.46 gm-atom) of 30 mesh granular zinc is added over a i hr period. After the addition has been completed, warming between 70°C and 80°C is continued for an... 

An ethanolic solution of sodium ethoxide is prepared by reacting 3 g of sodium with 300 ml of absolute ethanol. 30 g of estradiol are dissolved in the resultant solution and there are then added thereto, with stirring, 30 ml of n-propyl bromide. Reaction is continued for 3 hours with stirring at 60°C and then the reaction mixture is concentrated under vacuum at 30°C to about 50 ml. The residue is taken up in 500 ml of benzene and then washed twice with 250 ml of a 0.25 N solution of sodium hydroxide and then with distilled water to neutrality. The solution is then dried over sodium sulphate and concentrated to give 32 g of crude product (yield 93%), which on recrystallization from 100 ml of methanol gives 31 g (yield 89%) of pure product MP 100°-101°C. 

B. Ethyl a.-(hexahydt oaaepinylidene-S)aoetate. A solution of sodium ethoxide is prepared from 8.3 g (0.36 mol) of freshly cut sodium and 600 mL of freshly distilled absolute ethanol (Note 5) in a 1-L, round-bottomed flask equipped with a magnetic stirrer and fitted with a reflux condenser. To the stirred solution is added in one portion 71.7 g (0.30 mol) of freshly recrystallized isopropylidene a-(hexahydroazepinylidene-2)malonate. The mixture is refluxed and a white precipitate begins to appear. Refluxing is continued for 12 hr. The solvent is removed with a rotary evaporator and the white precipitate is placed in a 2-L beaker. Water (300 mL) is added and a 1 N hydrochloric solution is added dropwise to pH 6. The reaction mixture is extracted with four 100-mL portions of chloroform. The extracts are dried over anhydrous sodium sulfate and the solvent is removed with a rotary evaporator. The yellow solid residue is recrystallized from methanol to give 43-44 g (78-80%) of white powder, mp 55-56 C (Note 6). 

Add solution of 150 g 2-amino-6-nitrotoluene (prepared by reduction of 2,6-dinitrotoluene with HjS in ammoniacal ethanol and recrystallize-water or ethanol) in 550 g concentrated sulfuric acid slowly to 5 Kg crushed ice and then add dropwise a solution of 75 g Na nitrite in 100 ml water with stirring and cool (0-5°). Continue stirring two hours and add 2 L 10% sulfuric acid containing 0.1% Cu sulfate. Heat at 75-80° twelve hours or until Nj evolution ceases. Filter, cool to precipitate 135 g 2-OH-6-nitrotoluene (I) (recrystallize-aqueous ethanol) (can also prepare by nitrating o-cresol). Add 20 g (I) in 100 methanol to a solution of 5.8 g Na metal in 60 ml methanol or ethanol. Add dropwise with stirring, 34 g diethyl or dimethylsulfate. After addition reflux one hour, evaporate in vacuum most of the methanol, add 100 ml water and extract with 3X50 ml ether. Wash ether with 50 ml 5% NaOH, 2X50 ml water dry, filter, evaporate in vacuum (can distill 116/2.2 for ethyl-, 94-6/0.5 for methyl-) to get 20 g 2-alkyloxy-6-nitrotoluene (II). Can also use 1-Br-propane and reflux four hours evaporate in vacuum the ether extract and distill residue (180/17) to get the 2-n-propoxy-6-nitrotoluene (recrystallize-aqueous methanol). To a suspension prepared from 7.8 g K metal (Na may do) and 25 ml absolute ethanol in 160 ml dry ether, add dropwise a solution of 0.1 M (II)... 

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