Temperature filters

Prepare 10 ml. of saturated sodium bisulphite solution and add 4 ml. of the aldehyde shake thoroughly and observe the rise in temperature. Filter the crystalline precipitate at the pump, wash it with a little alcohol, followed by ether, and allow it to dry. 

C. Fumaric acid from furfural. Place in a 1-litre three-necked flask, fitted with a reflux condenser, a mechanical stirrer and a thermometer, 112 5 g. of sodium chlorate, 250 ml. of water and 0 -5 g. of vanadium pentoxide catalyst (1), Set the stirrer in motion, heat the flask on an asbestos-centred wire gauze to 70-75°, and add 4 ml. of 50 g. (43 ml.) of technical furfural. As soon as the vigorous reaction commences (2) bvi not before, add the remainder of the furfural through a dropping funnel, inserted into the top of the condenser by means of a grooved cork, at such a rate that the vigorous reaction is maintained (25-30 minutes). Then heat the reaction mixture at 70-75° for 5-6 hours (3) and allow to stand overnight at the laboratory temperature. Filter the crystalline fumaric acid with suction, and wash it with a little cold water (4). Recrystallise the crude fumaric acid from about 300 ml. of iif-hydrochloric acid, and dry the crystals (26 g.) at 100°. The m.p. in a sealed capillary tube is 282-284°. A further recrystaUisation raises the m.p. to 286-287°. 

To the clear solution obtained by warming 0-5 g. of 2 4-dinitro-phenylhydrazine, 1 ml. of concentrated hydrochloric acid and 8- 10 ml. of ethanol, add 0-25 g. of the aldehyde and heat just to boiling. Allow to cool to room temperature, filter off the 2 4-dinitrophenylhydiuzone and recrystallise it from ethanol or glacial acetic acid. 

Hydrolysis of methyl m-nitrobenzoate to m-nitrobenzoic acid. Place 90 -5 g. of methyl m-nitrobenzoate and a solution of 40 g. of sodium hydroxide in 160 ml. of water in a 1-htre round-bottomed flask equipped with a reflux condenser. Heat the mixture to boiling during 5-10 minutes or until the ester has disappeared. Dilute the reaction mixture with an equal volume of water. When cold pour the diluted reaction product, with vigorous stirring, into 125 ml. of concentrated hydrochloric acid. Allow to cool to room temperature, filter the crude acid at the pump and wash it with a httle water. Upon drying at 100°, the crude m-nitrobenzoic acid, which has a pale brownish colour, weighs 80 g. and melts at 140°, Recrystalhsation from 1 per cent, hydrochloric acid afibrds the pure acid, m.p. 141°, as a pale cream sohd the loss of material is about 5 per cent. 

Place an intimate mixture of 125 g. of powdered, anhydrous zinc chloride and 26-5 g. of acetophenonephenylhydrazone in a tall 500 ml. beaker in an oil bath at 170°. Stir the mixture vigorously by hand. After 3-4 minutes the mass becomes hquid and evolution of white fumes commences. Remove the beaker from the bath and stir the mixture for 5 minutes. Then stir in 100 g. of clean, white sand in order to prevent solidification to a hard mass. Digest the mixture for 12-16 hours on a water bath with 400 ml. of water and 12 ml. of concentrated hydrochloric acid in order to dissolve the zinc chloride. Filter off the sand and the crude 2-phenylindole, and boil the solids with 300 ml. of rectified spirit. Treat the hot mixture with a little decolourising carbon and filter through a pre-heated Buchner funnel wash the residue with 40 ml. of hot rectified spirit. Cool the combined filtrates to room temperature, filter off the 2-phenylindole and wash it three times with 10 ml. portions of cold alcohol. Dry in a vacuum desiccator over anhydrous calcium chloride. The yield of pure 2-phenylindole, m.p. 188-189°, is 16 g. 

The purple quinizarin solution is next saturated with carbon dioxide and the precipitated quinizarin again filtered. The product is then boiled with 5 1. of a 10 per cent solution of sodium carbonate until it appears black (probably the mono-sodium salt) to dissolve the last traces of purpurin. The mixture is cooled to room temperature, filtered, and the precipitate boiled with 5 1. of 5 per cent hydrochloric acid to liberate the quinizarin. The mixture is again cooled to room temperature and the final product filtered, washed with cold water and dried at 100°. 

Purification methods described for the mixed isomers are applicable. The individual isomers can be separated by very efficient fractional distn, followed by fractional crystn by partial freezing. The cz5-isomer reacts preferentially with AICI3 and can be removed from the /ranj-isomer by stirring the mixture with a limited amount of AICI3 for 48h at room temperature, filtering and distilling. 

The d5-l,2-cyclodecanediol will have crystallized out of solution, while the trans-Aio remains in the ethanol. The entire mixture is washed out of the bomb with 95% ethanol (about 11.). The cis-glycol is redissolved by heating the ethanolic mixture at reflux temperature. Filter aid ( Celite ) is added to the mixture, and the hot mixture is filtered through a bed of filter aid on a Buchner funnel to remove the catalyst. The ethanol is... 

Compound 1567 CB and chloracetone are caused to react as in (B), the mineral salts subsequently filtered, 12 ml of concentrated hydrochloric acid are added to the solution in dimethyl formamide without dilution with water, and the mixture heated for 40 minutes on a water bath. The product crystallizes in the warm mixture, the mixture is cooled to room temperature, filtered, the residue washed with water and crystallized from acetic acid. MPc = 222°C. Yield 60% based on compound 1567 CB. 

It is cooled to ambient temperature, filtered, and the methanol is evaporated to dryness. 13.2 g methyl 3-(p-chlorobenzoyl)-3-thloacetylpropionate in the form of a chromatographically pure orange-colored oil are obtained. 

The 1-(4-acetamidophenoxy)-2,3-epoxypropane used as starting material may be obtained as follows. To a solution of 4.5 parts of 4-acetamidophenol and 1.5 parts of sodium hydroxide in 50 parts of water at 15 C, there is added 3.5 parts of epichlorohydrin. The mixture is stirred for 16 hours at ambient temperature, filtered and the solid residue is washed with water. There is thus obtained 1-(4-acetamidophenoxy)-2,3-epoxypropane, MP 110°C. 

Quinaldinic acid. Zinc > 100 mg in a solution acidified with acetic ( ethanoic) acid to pH 3-4. Heat to boiling and add 3 per cent sodium quinaldate solution with stirring until precipitation is complete (25 per cent excess should be used). Cool to room temperature, filter and wash the precipitate with cold water and then a little ethanol. Dry at 105-110 °C and weigh as Zn(C10H6O2N)2,H2O (Section 11.50). 

Saturated sodium sulphate solution. Prepare a saturated aqueous solution at 50 °C and cool to room temperature. Filter before use. 

If the composite is left only partially densified, it can be used as a filter for high temperature filtering systems with high collection efficiency as required in direct coal-fired gas and steam turbines. Similar systems are considered for particulate filtering in diesel engines by a carbon foam or felt coated with silicon carbide by CVI. 

Amino-3 5-diiodobenzoic acid. In a 2 litre beaker, provided with a mechanical stirrer, dissolve 10 g. of pure p-aminobenzoic acid, m.p. 192 (Section IX,5) in 450 ml. of warm (75 ) 12-5 per cent, hydrochloric acid. Add a solution of 48 g. of iodine monochloride (1) in 40 ml. of 25 per cent, hydrochloric acid and stir the mixture for one minute during this time a yellow precipitate commences to appear. Dilute the reaction mixtiu e with 1 litre of water whereupon a copious precipitate is deposited. Raise the temperature of the weU-stirred mixture gradually and maintain it at 90 for 15 minutes. Allow to cool to room temperature, filter, wash thoroughly with water and dry in the air the yield of crude acid is 24 g. Piuify the product by dissolving it in dilute sodium hydroxide solution and precipitote with dilute hydrochloric acid the yield of air-dried 4-amino-3 5-diiodobenzoic acid, m.p. > 350 , is 23 g. 

On the other hand, in order to preserve the cold properties of the fuel (Cloud Point, Pour Point and low-temperature filterability), it is mandatory not to increase the melting point, that in turn depends on both the saturated compound (stearic acid, C18 0) content and the extent of cis/trans and positional isomerization as the difference in melting point between the cis and trans isomer is at least 15°C according to double bond position as shown in Table 1. 

Preparation of Inulin. Comminute the tubers or roots in a food chopper or similar appliance and express the juice with a tincture press, using, if necessary, a small portion of water to complete the extraction. Heat the juice to 60-70° and add milk of lime to about pH 8. Filter and adjust the pH to 7 with oxalic acid. Heat to 70-80°, add activated carbon and filter. Allow the filtrate to stand quiescent overnight, during which time the inulin separates in the form of small spheroids. The yield may be increased by freezing the solution and allowing it to thaw at a low temperature. Filter and wash the inulin with abundant quantities of cold water. 

Cleaning of the generated gas from particulates in a high-temperature filter. 

Note about infrared radiation (IR) filters In the bolometer just described, the optimum conductance to the heat sink is G 2 x 10-10 W/K. This means that an absorbed power of the order of 1(T10 W saturates the bolometer. Since the bolometer is a broad-band detector, it would receive, e.g., a power of the order of 10 7 W from a 30 K black body. Of course, optical filtering is needed to reduce the bandwidth of the impinging radiation. Filtering takes usually place in several steps a room temperature filter eliminates visible light an intermediate temperature filter (at about 77 K) rejects the micron wavelengths, whereas the submillimetre or millimetre filter is made up of a low-pass and an interference band-pass filter. 

Mix 294g (1.6M) 1,3,5-trichlorobenzene, 184g (3.4M) Na methoxide and 450g (3 3M) diglyme and reflux at 162° C for 42 hours. Cool to room temperature, filter and distill the solvent to get 70% yield of l-Cl-3,5-dimethoxybenzene (I). 43.2g (I) in 540 ml tetrahydrofuran is added dropwise to 7.3g Mg, a small crystal of iodine and a few drops of ethyl bromide (under nitrogen if possible) over Vi hour while the mixture is heated to 75° C. Reflux 2 hours and cool to room temperature to obtain the Grignard solution. 

Prepare 6-methoxy-l-indanone (I) (JCS 1986(1962)) using polyphosphoric acid made by diluting 500 g of the commercial acid with 120 g 85% phosphoric acid. 2.5 g (I) in 176 ml ether and reflux one hour with 0.27 g lithium aluminum hydride. Cool and carefully add water and filter when bubbling stops (can use Celite filter aid). Dry and evaporate in vacuum and store twelve hours at -15° (under N2 if possible) to precipitate the white 6-methoxy-l-indanol (II) (recrystallize-n-hexane). 2.5 g (II) in 73 ml benzene and reflux one-half hour with 0.2 g p-toluenesulfonic acid. Cool, add water and separate the phases. Extract the aqueous phase with ether and combine with benzene phase and dry, evaporate in vacuum to get 5-methoxy-indene (III) (can distill 110-45/10). 1.53 g (III) and 1.39 g N.N-diethyl-aminoethyl-Cl.HCI in benzene (prepare the free base in benzene as described previously). Reflux four hours with 0.42 g sodamide, cool, wash with water and dry, evaporate in vacuum to get the indene analog of 6-methoxy DET as a dark liquid (can crystallize as oxalate). Alternatively, dissolve 2.51 g (III) in ether and treat (under N if possible) with 12 ml 1.6M buty-Li in hexane at 0-10°. After two hours cool to -30° and add 12 ml more of butyl-Li. Add ether suspension of 2.5 g N,N-diethylaminoethyl-CI. HCI over one-half hour and warm to room temperature. Filter, evaporate in vacuum to get the 6-methoxy-DET analog. 

C. (Alternative) To 0.1M ethyl-chloroformate in 100 ml CHCI3 at -30° add a cold solution of 0.1 M (II) and 0.1 M triethylamine in 100 ml CHCI3 over forty minutes. Stir 1 /z hours at -20° to 5° and bubble NH3 through the cold mixture for twenty minutes. Stir one-half hour at room temperature, filter and extract the solid with CHClj. Combine CHCI3 extracts and filtrate and wash two times with cold NaOH solution and two times with water. Dry and evaporate in vacuum to get (III). 

Dissolve 4 g glyoxylic acid monohydrate in 220 ml water and add with stirring to a solution of 10 g 4,5, or 6 methoxy-tryptamine-HCl in 80 ml water. Adjust pH to 4 with 10% KOH and stir five hours at room temperature. Filter and wash with water to get about 4.5 g precipitate. Melt to decarboxylate or to 4 g precipitate add 30 ml concentrated HCI and 100 ml water and heat at 65° one hour. Add water to dissolve the solid and add excess 10% KOH. Filter to get the title compound or analog. 

II). To a warm solution of 5.2 g urotropine (hexamethylenetetramine) in 45 ml CHCI3, add 8 g (II) in 10 ml CHCI3 and let stand four hours at room temperature. Filter, wash with CHC13 and dry. Dissolve 2.3 g precipitate in 10 ml concentrated HCI and let stand two hours at room temperature. Add 30 ml water, basify with NaOH and extract with ether. Precipitate with dry HCI gas to get 3-Br-5-aminomethyl-isoxazole (III). Test for activity. Dissolve 8.8 g... 

When the reaction is complete, as shown by GLC analysis, the mixture is cooled to room temperature, filtered, and H20 (50 ml) is added. The organic phase is separated, dried (CaS04), and fractionally distilled to yield the carbonate [e.g. (PhCH20)2C0, 61% (MeO)2CO, 63% (4-MeC6H4CH20)2C0, 88%]. 

The alkene (10 mmol) is added over 2 h to the methylene compound (15 mmol), K2C03 (3.3 g), I2 (3 g) and Aliquat (0.1 g, 0.2 mmol) in refluxing PhMe (10 ml). The mixture is cooled to room temperature, filtered, and evaporated. The residue is taken up in PhMe (10 ml) and the solution is washed well with aqueous Na2S203 (10%), dried (Na2S04), and evaporated to yield the cyclopropane (Table 6.20). 

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