Ammonium sulfate recrystallization

The mixture is allowed to warm up over 20 minutes and is poured into a 2-1. separatory funnel. The purplish solution is washed with a saturated ammonium sulfate solution (about 1.5 1.) containing ferrous ammonium sulfate until the rust-brown ferric color is no longer produced. The organic layer is dried over magnesium sulfate and concentrated, leaving a dark solid. Purification of the solid by high-vacuum short path distillation gives 127-142 g. (73-81%) of a pinkish or tan-colored product, b.p. 148-150° (0.15 mm.), m.p. 145-147°. It may be further purified by sublimation, or recrystallization from benzene-hexane, m.p. 148-149°. 

To a solution of 4.2 gm (0.0276 mole) of JV-methyl-A -phenyldiimide dioxide in 50 ml of anhydrous ether is added 185 ml of a 0.21 N solution of methyl magnesium chloride in anhydrous ether (0.0389 mole) over a 3 hr period while maintaining the reaction mixture at 20°C. Then the reaction mixture is cautiously heated with 100 ml of a saturated aqueous solution of ammonium sulfate. At this point 37 mg of an unidentified deep-red solid (m.p. 126°-127C C dec.) after recrystallization, m.p. 140.5°C dec., separates. This material is removed by filtration and discarded. 

The mixture was heated at 50-60°C, to the solution was added 20 g of sodium nitrite and then at 40-60°C was added dropwise the mixture of 6 L of concentrated HN03, 4.2 L of water and 30 g of sodium nitrite. The product obtained was mixed with 2.4 kg ammonium sulfate and filtrated. The filtrate was heated with 14.5 kg urea at 70°C for 10 hours. Allantoin was filtrated and recrystallized from the water M.P. 233-235°C. 

Summary Anhydrous ammonia can be prepared by treating an ammonium salt solution with a solution of sodium hydroxide. In the following procedure, ammonium chloride or ammonium sulfate is treated with sodium hydroxide to yield ammonia gas, which is then dried to yield the anhydrous gas. The ammonium chloride or sulfate can be prepared by neutralizing 10% ammonia (store bought ammonia) with hydrochloric or sulfuric acids, followed by recrystallization. 

Recrystallization. The suspension of crystals obtained above is centrifuged (20,000 r.p.m. at 0°) and the crystals are dissolved in M/30 phosphate buffer, pH 6.0, containing 5% of sodium chloride, to a concentration of about 30 mg. of protein/ ml. The protein dissolves slowly, but completely, in 1-2 hours. The concentration of ammonium sulfate is estimated with Nessler reagent." By adding a saturated solution of ammonium sulfate as above, the concentration is raised to s 0.23. The solution is then nucleated with /3-galactosidase crystals, and is further stirred. Crystals begin to appear after H hour, and the process is complete in 24-36 hours. The product has a specific activity of 575,000 yield, 65%. 

Acetylene is passed for 1 hr through a mixture consisting of 0.5 g (72 mg-atoms) of lithium in 100 ml of ethylene-diamine. A solution prepared from 1 g (3.5 mmoles) of rac-3-methoxy-18-methylestra-l,3,5(10)-trien-I7-one and 30 ml of tetrahydrofuran is then added at room temperature with stirring over a period of 30 min. After an additional 2 hr during which time acetylene is passed through the solution the mixture is neutralized with 5 g of ammonium chloride, diluted with 50 ml water, and extracted with ether. The ether extracts are washed successively with 10% sulfuric acid, saturated sodium hydrogen carbonate and water. The extract is dried over sodium sulfate and concentrated to yield a solid crystalline material, which on recrystallization from methanol affords 0.95 g (87%) of rac-3-methoxy-18-methyl-17a-ethynyl-estra-l,3,5(10)-trien-17jB-ol as colorless needles mp 161°. 

A three-necked round-bottom flask is fitted with a dropping funnel, a thermometer, and a magnetic stirrer and is heated in a water bath to 30°. Tetralin (1.32 g, 0.01 mole) and 50 ml of 3.5 Anitric acid solution are placed in the flask and brought to temperature. Ceric ammonium nitrate (21.9 g, 0.04 mole) is dissolved in 100 ml of 3.5 N nitric acid, and the solution is added dropwise to the reaction mixture at a rate such that the temperature does not rise and only a pale yellow color is evident in the reaction mixture. At the completion of the reaction (1 to 2 hours), the mixture should be colorless. The solution is cooled to room temperature, diluted with an equal volume of water, and extracted twice with ether. The ether solution is dried with anhydrous sodium sulfate, filtered, and the ether is evaporated. The residue may be distilled to yield a-tetralone (bp 113-11676 mm or 170749 mm) or may be converted directly to the oxime, which is recrystallized from methanol, mp 88-89°. 

A) Preparation of p-Hydroxy-p -Methoxybemhydrylidenecyclohexane To a Grignard solution prepared from 110 g of magnesium (4.5 mols) and 840 g of p-bromoanisole (4.5 mols) in one liter of anhydrous ether, there was added dropwise with vigorous agitation 307 g of p-hydroxyphenyl cyclohexyl ketone (1.5 mols) dissolved in one liter of anhydrous ether. Upon completion of the addition the reaction mixture was refluxed for 2.5 hours with agitation, and was then cooled. Thereupon 15 mols of ammonium chloride dissolved in 3 liters of water were added. The ethereal layer was separated, washed with water, dried over anhydrous sodium sulfate and distilled. Yield 370 g. BP 180° to 190°C at 0.1 mm. The substance was recrystallized from a mixture of carbon tetrachloride and petroleum ether. MP 145° to 146°C. 

The mixture was heated under reflux and a solution of 0.2 g of ethyl iodide in 5 ml of dry tetrahydrofuran was allowed to flow into the reaction medium. When the reaction started, a solution of 6.2 g of 7heated under reflux until the complete disappearance of the magnesium turnings. The reaction medium was then cooled in an ice bath, after which there was added thereto a solution in 45 ml of tetrahydrofuran of 7 g of 6-oxo-benzo[b] -benzofurano[2,3-e] oxepin. The reaction mixture was allowed to stand for 20 hours at a temperature of 20°C, and was then poured into a saturated aqueous solution of ammonium chloride maintained at a temperature of 5°C. The mixture was extracted with ether and the organic portion was washed and dried over anhydrous sodium sulfate. After evaporation of the solvent, 9.4 g of crude product were obtained, which after recrystallization from isopropanol, provided 6.7 g of pure 6-(3-dimethylam nopropyl)-8-hydroxybenzo[b] benzofurano-[2,3-e] oxepin, melting point 160°C (yield, 71 %). 

To a solution of 2 mols of methylmagnesium iodide in 1.5 liters of ether are added with vigorous stirring 107 g (0.5 mol) of ethyl p-chloroatrolactate. The reaction mixture is stirred for about sixteen hours, and is then decomposed by the addition of about 320 ml of saturated aqueous ammonium chloride solution. After standing, the ether layer is decanted from the mixture and the aqueous phase and the precipitated salts are washed with several 500 ml portions of ether. The combined ether solution and washings are washed with successive 500 ml portions of 5% ammonium chloride solution and water, are dried over anhydrous magnesium sulfate, and are evaporated to dryness in vacuo. The crystalline residue consisting of 2-p-chlorophenyl-3-methyl-2,3-butanediol, is recrystallized from a mixture of benzene and petroleum ether. 

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