Solids weighing

The general reaction procedure and apparatus used are exactly as described in Procedure 2. Ammonia (465 ml) is distilled into a 2-liter reaction flask and to this is added 165mlofisopropylalcoholandasolutionof30g(0.195 mole) of 17/ -estradiol 3-methyl ether (mp 118.5-120°) in 180 ml of tetrahydrofuran. The steroid is only partially soluble in the mixture. A 5 g portion of sodium (26 g, 1.13 g-atoms total) is added to the stirred mixture and the solid dissolves in the light blue solution within several min. As additional metal is added, the mixture becomes dark blue and a solid (matted needles) separates. Stirring is inefficient for a few minutes until the mass of crystals breaks down. All of the sodium is consumed after 1 hr and 120 ml of methanol is then added to the mixture with care. The product is isolated as in Procedure 4h 2. After being air-dried, the solid weighs 32.5 g (ca. 100% for a monohydrate). A sample of the material is dried for analysis and analyzed as described in Procedure 2 enol ether, 91% unreduced aromatics, 0.3%. The crude product may be crystallized from acetone-water or preferably from hexane. 

The reaction product mixture is a homogenous solution having a pH of about 6. It is evaporated under vacuum to a semisolid residue. To the residue are added 35 ml of water and a few drops of triethylamine to raise the pH to 8. The aqueous solution obtained thereby is extracted successively with 50 ml and 35 ml portions of ethyl acetate, the pH being adjusted to 2 at each extraction with hydrochloric acid. The extracts are combined, filtered, dried over sodium sulfate, stripped of solvent, and evaporated under vacuum. The product is 7-(N-carbobenzoxy-D-o -aminophenylacetamido)cephalosporanic acid in the form of a yellow-white amorphous solid weighing 1.10 g. 

A solution of 32 g (030 mol) phosgene in 200 ml benzene is added dropwise at 30°C to a stirred soiution of 53.5 g (032 mol) 3-o-toloxy-13-Pfopanediol in 400 ml benzene. The mixture is stirred for an hour after the addition is completed, and a solution of 39 g of dl-methylaniline in 100 ml benzene is then added, and stirring continued for a half-hour. Ice water (about one-third volume) is then added, and the benzene layer formed is separated and stirred with 500 ml concentrated ammonia at 5°Cfor six hours. The precipitated solid (weighing about 55 g) is recovered and recrystallized from water. The product thus obtained in a yield of about 53 g is 3-(o-toloxy)-2-hydroxypropyl carbamate it is a crystalline solid melting at about 93°C, and having a lower water-solubility and higher oil-solubility than 3-o-toloxy-13-propanediol. 

Thionyl chloride method. Mix 100 g. of pure p-nitrobenzoic acid and 126 g. (77 ml.) (1) of redistilled thionyl chloride in a 500 ml. round-bottomed flask. Fit the flask with a double surface reflux condenser carrying a calcium chloride (or cottou wool) guard tube and connect the latter to an absorption device e.g., Fig. II, 8, 1. c). Heat the flask on a water bath with occasional shaking for 1 hour or until the evolution of hydrogen chloride and sulphur dioxide ahnost ceases. Allow the reaction mixture to cool, transfer it cautiously to a Claisen flask connected with a water-cooled condenser and a receiver (compare Fig. II, 13, 1). Distil off the excess of thionyl chloride (b.p. 77°) slowly and continue the distillation until the temperature rises rapidly to about 120° this will ensure that all the thionyl chloride is remov. Allow to cool, and distil the residual p-nitrobenzoyl chloride under diminished pressure as detailed in the Phosphorus Pentachloride Method. The resulting p-nitrobenzoyl chloride (a yellow crystalline solid) weighs 107 g. and melts at 72-73°. 

Place 0.1 g of your solid (weighed to O.Olg) in a test tube. 

By dilution measure out 6.22 mL of the 4.021 M solution as precisely as possible (measuring pipet), dilute it to 100.0 mL (volumetric flask), and shake. By weight of the pure solid weigh out 2.650 g on an analytical balance, place in a 100-mL volumetric flask, dissolve in water, dilute to 100.0 mL, and shake. 

The solid is collected by suction filtration, washed with about 750 ml. of water, and dried overnight at 75-80° in an oven under reduced pressure (200 mm. or below). Dehydration to bis(10,9-borazarophenanthryl) ether usually takes place during the drying. The ether, a tan solid, weighs 221-250 g. (80-91%) (Note 8). 

A solution of 31.8 g (0.74 mole) of 3-(2-benzylmethylaminoacetyl) methanesulfonanilide methanesulfonate in 700 ml of absolute ethanol is reduced in an atmospheric hydrogenation unit (2 to 5 p.s.i. g positive pressure) during 24 hours with a 10% palladium catalyst prepared from 320 mg of palladium chloride and 2.0 g of pulverized charcoal. After absorption of the calculated amount of hydrogen, the catalyst is filtered, the filtrate concentrated to about 100 ml, mixed with about 500 ml of ether, resulting in precipitation of a white solid weighing 24.3 g (96%), M.P. 201-203.5°C. Two recrystallizations from ethanol (35 ml/g of solid) yield the analytically pure 3-(2-methylamino-l-hydroxyethyl)methanesulfonanilide methanesulfonate, 19.6 g (75%), M.P. 207-209°C. 

A 200-mg sample of a mineral containing oxygen but no sulfur is treated with an excess of BrFs, converting all oxides present to fluorides. The excess BrF3 is removed in vacuo, the resulting solid weighing 256 mg. 

In a 500-cc. three-necked, round-bottomed flask fitted with a reflux condenser, mechanical stirrer, and thermometer are placed 48.5 g. (0.22 mole) of the sodium sulfinate and 60 cc. of a mixture of 75 cc. of ethylene glycol and 120 cc. of carbitol or methyl car-bitol. The mixture is stirred and heated in an oil bath until solution is complete, after which 31.5 g. (0.2 mole) of 4-chloronitro-benzene (m.p. 76-78°) is added. The mixture is heated for three and a half hours at 141-143° (thermometer in the mixture), with continued stirring, and then is allowed to cool overnight. After addition of 20 cc. of water, the pasty lumps are broken up, and the solid is filtered with suction and washed with 50-75 cc. of hot water. The solid is then transferred to a 1-1. flask and refluxed with 250 cc. of 95 per cent alcohol for fifteen minutes. After cooling, the -nitro- -acetylaminodiphenylsulfone is filtered with suction and washed on the funnel, first with 25 cc. of alcohol and then with 25 cc. of ether. After drying in the air, the tan-colored solid weighs 32-33 g. (50-52 per cent of the theoretical amount) and melts at 226-228° (Note 2). 

The aqueous distillate is treated with 650 cc. of concentrated hydrochloric acid and concentrated on a steam bath, under reduced pressure, until the residual liquor becomes a syrupy mass (Note 3). This is desiccated further by adding 150 cc. of absolute ethyl alcohol and evaporating under reduced pressiue. Two or three such treatments with alcohol dry the crystalline material sufficiently so that it no longer sticks to the sides of the flask. The crude product is dried in a vacuum desiccator over calcium chloride. The pale yellow, dry, crystalline solid weighs 200-215 g. (77 3 cent of the theoretical amoimt). The dried product... 

Gravimetric factor, GF The. stoichiometric ratio between the analyte and the solid weighed in a gravimetric analysis. Gravimetric titrimetry Titrations in which the mass of standard titrant is measured rather than volume the concentration of titrant is expressed in mmol/g of solution (rather than the more familiar mmol/mL). 

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