Fortis

Unfortimately for modem crystallographers, all of tlie crystal stmctiires that could be solved by the choose-the-best-of-a-small-niunber-of-possibilities procedure had been solved by 1920. Bragg has been quoted as saying that the pyrite stmcture was very complicated , but he wrote, in about 1930, It must be realized, however, that (cases having one or two parameters) are still extremely simple. The more typical crystal may have ten, twenty, or forty parameters, to all of which values must be assigned before the analysis of the stmcture is complete. This statement is read with amusement by a modem crystallographer, who routinely works with hundreds and frequently with thousands of parameters. 

Drickamer H G 1990 Forty years of pressure tuning spectroscopy Ann. Rev. Mater. Sc/. 20 1... 

Staehle R W, Forty A J and Rooyen D v (eds) 1969 Fundamental Aspeots of Stress Corrosion Craoking (Houston, TX NACE)... 

The treatment is at the upperclass undergraduate or beginning graduate level. Considerable introduetor y material and material on eornputational methods are given so as to make the book suitable for self-study by professionals outside the elassroom. An effort has been made to avoid logieal gaps so that the presentation ean be understood without the aid of an instruetor. Forty-six self-eontained eomputer projeets are included. 

Until the end of the forties, when the HMO method was first applied to thiazole, most of the experimental results concerning its chemical reactivity remained of a qualitative nature. Papers devoted to the subject... 

Furan hot-box resins are used in both ferrous and nonferrous foundries (66,67). In this process, resin and catalyst are intimately mixed with dry sand and then blown into heated metal boxes containing a cavity the shape of the desired core. In seconds, the surface of the sand mass hardens and, as soon as the core has cured sufficiently to be rigid and handleable the box is opened and the core removed. Automotive cores with exceUent dimensional accuracy and high strengths are made via this forty-year-old process. 

The solvent and initiator are charged to the reactor and heated to reflux (ca 80°C). Forty percent of the monomer charge is then added. The remainder of the monomer is added in four equal increments at 24, 50, 79, and 110 min after addition of the initial monomer charge. The reaction mixture is kept at reflux overnight, then cooled and packaged (96). 

The two principal appHcations of countercurrent flow are found in the Beckman elutriators and the Haemonetics apheresis equipment. The Beckman elutriators are capable of very specific cell separation of small batches of cells. The Haemonetics surge technique can separate platelets and lymphocytes from four Hters of donor blood in one hour and forty minutes. 

E. S. Eiordan, Jr. andj. H. Saunders, eds.. Forty Years of Melt Spinning, American Chemical Society, Washington, D.C., 1981. 

Heat resistance is improved markedly by resin impregnation. A block of impreg, subjected to forty-five 1-h exposures at 204°C, showed no apparent loss in properties, although an untreated sample showed signs of deterioration after three 1-h exposures (71). 

Subsequently, other structural variations were reported encompassing compounds such as PS-5 (5) (5), carpetimycin A (6) (6), asparenomycin A (7) (7), and pluracidomycin A (8) (8), from a wide variety of streptomycete strains. Following these stmctures the simplest member of the series, having the completely unsubstituted nucleus, (1, X = CH2), was isolated from bacterial strains of Serratia and Ervinia (9). AH other natural products reported have substituents at both the C-6 and C-2 positions of the bicycHc ring system. Differences in the nature and stereochemistry of these substituents has provided a wide variety of stmctures, and over forty variations have been reported and comprehensively Hsted (10). 

Garbapenem P-Lactamase Inhibitors. Carbapenems are another class of natural product P-lactamase inhibitors discovered about the same time as clavulanic acid. Over forty naturally occurring carbapenems have been identified many are potent P-lactamase inhibitors. Garbapenem is the trivial name for the l-a2abicyclo[3.2.0]hept-2-ene ring system (21) shown in Table 3. The synthesis (74), biosynthesis (75), and P-lactamase inhibitory properties (13,14,66) of carbapenems have been reviewed. Carbapenems are often more potent than clavulanic acid and include type I Cephases in the spectmm of inhibition. Table 3 Hsts the available P-lactamase inhibition data. Synergy is frequendy difficult to demonstrate because the compounds are often potent antibacterials. 

A third study (85) enrolled 7825 hypertensive patients (55% males and 45% females) having diastoHc blood pressures (DBP) of 99—104 mm Hg (13—14 Pa) there were no placebo controls. Forty-six percent of the patients were assigned to SC antihypertensive dmg therapy, ie, step 1, chlorthaUdone step 2, reserpine [50-55-5] or methyldopa [555-30-6], and step 3, hydralazine [86-54-4]. Fifty-four percent of the patients were assigned to the usual care (UC) sources in the community. Significant reductions in DBP and in cardiovascular and noncardiovascular deaths were noted in both groups. In the SC group, deaths from ischemic heart disease increased 9%, and deaths from coronary heart disease (CHD) and acute myocardial infarctions were reduced 20 and 46%, respectively. 

Aerial parts of N. sintenisii yielded 0.3% of a clear yellowish oil. Forty constituents (96.5% of the total oil) were identified. The main components were 4aP,7a,7aP-nepetalactone (23.4%), elemol (16.1%), E- -farnesene (9.5%), 1,8-cineole (8.2%), cw-sabinene hydrate (6.5%), P-bisabolene (4.2%), germacrene-D (3.5%), P-sesquiphellandrene (2.8%), P-bourbonene (1.5%) and a-epi-cadinol (1.3%). According to available data, Nepeta species can be divided into two groups of nepetalactone-containing and nepetalactone-free species. The results of this study indicate that the compositions of volatile oil of N. sintenisii are similar to the other Nepeta genus and this plant could be classified in the group which 4aP,7a,7aP-nepetalactone is the major component of their oils. 

In a i-l. three-necked, round-bottom flask fitted with a mechanical stirrer through a mercury seal, a separatory funnel and an efficient reflux condenser to which a calcium chloride tube is attached, are placed 25 g. (1.03 moles) of magnesium turnings 140 cc. of dry ether, and a small crystal of iodine. The stirrei is started and a small portion (about 10 cc.) of a solution of 118.5 g. (i mole) of cyclohexyl bromide (Note i) in 120 cc. of dry ether is added through the separatory funnel. After the reaction starts, the remainder of the solution is run in at such a rate that the whole is added at the end of forty-five minutes. The mixture is stirred and refluxed for an additional thirty to forty-five minutes. 

A. Preparation of Thiocarbonyl Per chloride.—In a 5-I. bottle arranged for cooling by running water is placed 500 g. (6.58 moles) of dry carbon disulfide (Note i) to which 0.5 g. of iodine has been added. Dry chlorine is passed into the cooled carbon disulfide at such a rate that the temperature does not rise above 25°, until the liquid weighs 1770 g. (17.9 moles chlorine) (Note 2). The time required is about forty hours. The product is a deep red liquid, a mixture of impure thiocarbonyl perchloride and sulfur chloride. 

If the nutmegs be crushed to No. 40 powder, as recommended by the authors, the extraction is complete in twenty-four to forty-eight hours in checking it was found more convenient merely to pass the nutmegs through a food chopper (whereby they were broken up into pieces the largest of which were 3-4 mm. across), when the extraction required sixty-six to seventy-two hours for completion. 

To 500 g. (3.85 moles) of freshly distilled ethyl acetoacetate in a i-l. flask set in ice and well cooled, are added 152 g. (2.0 moles) of 40 per cent aqueous formaldehyde solution and 20-25 drops of diethylamine. The flask and contents are kept cold for six hours and are then allowed to stand at room temperature for forty to forty-five hours. At the end of this time two layers are present, a lower oily layer and an upper aqueous layer. The layers are separated, and the aqueous layer is extracted with 50 cc. of ether. The ether solution is added to the oily layer, and the resulting solution is dried over 30 g. of calcium chloride. The ether is then removed by distillation on a steam bath. The residue, amounting to approximately 500 g., is diluted with an equal volume of alcohol and is thoroughly cooled in an ice bath. Ammonia is then passed into the mixture until the solution is saturated. This requires from four to eight hours, and during this time the flask is kept packed in ice. The ammoniacal alcoholic solution is allowed to stand at room temperature for forty to forty-five hours. Most of the alcohol is now evaporated the residue is cooled, and the solid i,4-dihydro-3,5-dicarbethoxy-2,6-dimethylpyridine is removed from the remaining alcohol on a suction filter. The dried ester melts at 175-180 and amounts to 4ro-435 g. (84-89 per cent of the theoretical amount). 

A solution of 130 g. (0.52 mole) of this ester in 400 cc. of ethyl alcohol is placed in a two-necked 2-I. flask, carrying a dropping funnel and a reflux condenser, and is heated to boiling. Then one-third of a solution (Note 2) of 78.5 g. (1.4 moles) of potassium hydroxide in 400 cc. of alcohol is added from the dropping funnel, and the alcoholic solution is boiled until it becomes clear. Then a second third of the alkali solution is added, and the reaction mixture is again boiled until any precipitate disappears. Finally, the last third of the alcoholic potassium hydroxide solution is added. The addition of the alkali requires about twenty minutes. The reaction mixture is then boiled for forty minutes longer. 

D. Methionine.—A suspension of 21.5 g. (0.063 mole) of this tricarboxylic acid in 350 cc. of hot water is heated on the steam bath and 40 cc. of concentrated hydrochloric acid (sp. gr. 1.19) is added. Carbon dioxide is immediately evolved and the substance goes into solution. After heating for one and a half hours, 200 cc. more of concentrated hydrochloric acid is added and heating is continued for forty-five minutes longer. The solution, on cooling, deposits phthalic acid this is filtered off and washed with two 50-cc. portions of water (Note 3). The combined filtrate and washings are evaporated to dryness on the steam bath under reduced pressure, and the dry residue is dissolved in... 

In a foo-cc. three-necked, round-bottomed flask provided with a mechanical stirrer, a dropping funnel, and a thermometer well, are placed 40 g. (0.333 mole) of mesitylene (Org. Syn. Coll. Vol. I, 334) and 60 g. (55.5 cc.) of acetic anhydride (Note i). The flask is placed in a bath of ice and water, and, when the reaction mixture is cold (below lo ), addition is begun of a mixture of 31.5 g. (20.8 cc., 0.5 mole) of fuming nitric acid (sp. gr. 1.51) in 20 g. (19.1 cc.) of glacial acetic acid and 20 g. (18.5 cc.) of acetic anhydride (Note 2). The nitric acid solution is added with stirring over a period of forty minutes, keeping the temperature between 15° and 20°. 

Nitric acid, or aqua fortis as it was called in medieval times, has been known and used by mankind for centuries. At first, it was produced by heating a mixture of sodium nitrate (Chile saltpeter) and sulfuric acid. The product obtained was sodium hydrogen sulfate, and the nitric acid vapors escaping during this process were condensed ... 

Three hundred and forty-five grams (1.7 moles) of ethyl ethoxalylpropionate, b.p., ii4-ii6°/io mm. (p. 54), is placed in a round-bottomed flask, of suitable size carrying a reflux condenser, and a thermometer is suspended from the top of the condenser into the liquid. The ethyl ethoxalylpropionate is then heated until a Aigorous evolution of carbon monoxide begins (130-150 ). The temperature of the liquid is gradually raised as the gas evolution diminishes, and finally the liquid is refluxed until no more gas comes off. The ethyl methylmalonate is then distilled. It boils at ig4-iq6 /745 mm., and the yield is 288 g. (97 per cent of the theoretical amount). 

In a 3-I. flask are placed a solution of 184 g. (4.6 moles) of sodium hydroxide in 300-400 cc. of water and sufficient ice to make the total volume about 1500 cc. Chlorine is passed into the solution, keeping the temperature below 0° by means of a salt-ice bath, until the solution is neutral to litmus (Note i). After the addition of a solution of 34 g. of sodium hydroxide in 50 cc. of water, the flask is supported by a clamp and equipped with a thermometer and an efficient stirrer. The solution is warmed to 55°, and 85 g. (0.5 mole) of methyl d-naphthyl ketone (Note 2) is added. The mixture is vigorously stirred and, after the exothermic reaction commences, the temperature is kept at 60-70° (Note 3) by frequent cooling in an ice bath until the temperature no longer tends to rise. This requires thirty to forty minutes. The solution is stirred for thirty minutes longer and then the excess hypochlorite is destroyed by adding a solution of 50 g. of sodium bisulfite in 200 cc. of water (Note 4). After cooling to room temperature, the reaction mixture is transferred to a 4-I. beaker and carefully acidified with 200 cc. 

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