Reagents sodium sulfate

The mixture is distilled until most of the ether has been removed and then refluxed for 8 hr. Ethyl acetate is added to decompose the excess reagent and concentrated aqueous sodium sulfate is then added until the precipitate begins to adhere to the sides of the flask. Finally ca. 100 g of solid sodium sulfate is added, the salts are removed by filtration and washed well with dioxane. Evaporation of the solvent gives a solid residue which is dissolved in 60 ml of chloroform and shaken with 3.5 g of manganese dioxide for 16 hr. Subsequently another 3.5 g of manganese dioxide is added and shaking continued for a further 16 hr. The solid is removed by filtration and washed well with hot chloroform. Evaporation of solvent and crystallization of the residue from acetone-hexane affords 0.51 g (72%) of 17a-hydroxy-17jff-ethylandrost-4-en-3-one mp 145-148°. 

A mixture of 1.38 grams of the above compound and 15 cc of dioxane was treated with 1.9 cc of a 0.5 N aqueous solution of perchloric acid and 600 mg of N-bromoacetamide, adding the latter in the dark, in three portions, in the course of half an hour and under continuous stirring. It was then stirred for a further 1% hours in the dark, then the excess of reagent was decomposed by the addition of aqueous sodium bisulfite solution and ice water was added the product was extracted with methylene chloride, washed with water, dried over anhydrous sodium sulfate and the solvent was evaporated under reduced pressure, thus giving a yellow oil consisting of the 16,21-diacetate of 6a-fluoro-9a-bromo-16o-hydroxy-hydrocortisone which was used for the next step without further purification. 

The chloroform phase is then removed, the aqueous phase extracted twice more with 200 ml of chloroform and the united extracts shaken out 4 times, each time with 200 ml of 2N sodium hydroxide solution. The alkaline solution is then rendered acid to Congo red reagent, using hydrochloric acid and extracted 3 times with chloroform. After drying over sodium Sulfate and evaporating the solvent, the residue is chromatographed on aluminum oxide (Activity Stage V). The substance eluted with benzene and benzene/chloroform (1 1) is recrystallized from chloroform/hexane (1 1) MP 107° to 109°C. 

Evaporation of a chloroform solution of benzoylhydroperoxide under reduced pressure yields a paste containing 20-30 per cent of hydroperoxide. On further evaporation this decomposes into benzoic acid. A chloroform solution of benzoylhydroperoxide when carefully dried over anhydrous sodium sulfate at o° may be kept exposed to light at room temperature for a number of days without appreciable decomposition. In order to obtain benzoylhydroperoxide free from the reagents used in its preparation, it is necessary to extract the product with chloroform, such extraction resulting in a loss of about 10 per cent,... 

Sodium sulfate, anhydrous, granular, reagent grade... 

Sodium sulfate, anhydrous, reagent grade Ethyl acetate, reagent grade Whatman ashless 40 Alter paper Cyclohexane, reagent grade... 

Acetone, acetonitrile, n-hexane, diethyl ether, sodium chloride, anhydrous sodium sulfate reagent grade (Wako Pure Chemical Inc., Japan)... 

Methanol, n-hexane, ethyl acetate, distilled water, sodium chloride, sodium sulfate, reagent grade for residue analysis (Wako Pure Chemical Industries, Ltd, Japan) Acetonitrile, methanol, distilled water, reagent grade for high-performance liquid chromatography... 

The metal chlorides normally used as chlorinating agents are the low-cost reagents sodium chloride and calcium chloride. Silicates, carbonates and sulfates can be chloridized... 

El-Brashy [51] reported the determination of primaquine and other antimalarials via charge-transfer complexes. Powdered sample of primaquine phosphate was dissolved in water and the solution was adjusted to an alkaline pH with 6 M ammonia and extracted with chloroform. The extract was dried with anhydrous sodium sulfate, filtered, and evaporated to dryness under nitrogen and the residue was dissolved in acetonitrile. Portions of the solution were mixed with 0.2% 7,7,8,8-tetracyanoquinodimethane, diluted with acetonitrile, and set aside for 10 min before the absorbance was measured at 845 nm versus a reagent blank. The calibration graphs were linear from 0.4 to 3 pg/mL and recovery was 98%. 

The ammonium chloride is dried at 110° for 24 hours. Reagent-grade chlorobenzene dried over sodium sulfate is distilled prior to use. 

Available from K K Laboratories or may be prepared in 89% yield by the following procedure. To a solution of 393 g. (2.63 moles) of sodium iodide in 1 1. of reagent grade acetone is added 394 g. (2.50 moles) of l-bromo-3 chloropropane (Aldrich Chemical Co.). After stirring 2 hours at room temperature, the mixture is filtered, the sodium bromide is washed with acetone, and the acetone is evaporated at reduced pressure. A dark iodine color is present along with some solid sodium salts. The oil is dissolved in ether, and the solution is washed with a 10% aqueous sodium thiosulfate solution. The ethereal layer is separated, dried over anhydrous sodium sulfate, and evaporated at reduced pressure to yield 454 g. of an oil that can be used without further purification. 

Cyclohexene The commercially available reagent was washed with aqueous solution of ferrous sulfate, dried with anhydrous sodium sulfate and distilled(bp.83.0°C). The distilled cyclohexene was passed through an alumina column. This process of purification was repeated three times. 

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