Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Cotton acids

Nanocrystalline Cellulose Wood, cotton. Acid Diameter 5-70... [Pg.837]

Chromatographic Separation of a Mixture of o- and p-Nitroaniline. Prepare a glass tube A (Fig. 24) in which the wider portion has a diameter of 3 cm. and a length of ca. 30 cm. the narrow portion at the base has a diameter of 5-7 mm. Wash the tube thoroughly (if necessary, with chromic acid, followed by distilled water and ethanol) and then dry. Insert a small plug of cotton-wool P as shown just within the narrow neck of the tube it is essential that this plug does not project into the wider portion of the tube. Clamp the tube in a vertical position. [Pg.49]

Method 1. Mix 1 0 g. of 3 5-dinitrobenzoic acid (Section IV,168) with 4 ml. of thionyl chloride in a dry 50 ml. conical flask fit a reflux condenser, carrying a plug of cotton wool at the upper end, into the flask and heat on a water bath for 15-30 minutes. Remove the condenser and heat the flask in a boiling water bath FUME CUPBOARD 1) until the excess of thionyl chloride has evaporated. Use the resulting 3 5-dinitrobenzoyl chloride (about 10 g.) immediately. [Pg.262]

In a 250 ml. separatory funnel place 25 g. of anhydrous feri.-butyl alcohol (b.p. 82-83°, m.p. 25°) (1) and 85 ml. of concentrated hydrochloric acid (2) and shake the mixture from time to time during 20 minutes. After each shaking, loosen the stopper to relieve any internal pressure. Allow the mixture to stand for a few minutes until the layers have separated sharply draw off and discard the lower acid layer. Wash the halide with 20 ml. of 5 per cent, sodium bicarbonate solution and then with 20 ml. of water. Dry the preparation with 5 g. of anhydrous calcium chloride or anhydrous calcium, sulphate. Decant the dried liquid through a funnel supporting a fluted Alter paper or a small plug of cotton wool into a 100 ml. distilling flask, add 2-3 chips of porous porcelain, and distil. Collect the fraction boiling at 49-51°. The yield of feri.-butyl chloride is 28 g. [Pg.276]

Stopper the side arm of a 25 or 50 ml. distilling flask and fit a vertical water condenser into the neck. Place 0-5-1 -0 g. of the dry acid (finely powdered if it is a solid) into the flask, add 2-5-5 0 ml. of redistilled thionyl chloride and reflux gently for 30 minutes it is advisable to place a plug of cotton wool in the top of the condenser to exclude moisture. Rearrange the condenser and distil off the excess of thionyl chloride t (b.p. 78°). The residue in the flask consists of the acid chloride and can be converted into any of the derivatives given below. [Pg.361]

Method B. In a 500 ml. round-bottomed flask, provided with a reflux condenser protected by a cotton wool (or calcium chloride) drying tube, place 59 g. of succinic acid and 102 g. (94-5 ml.) of redistilled acetic anhydride. Reflux the mixture gently on a water bath with occasional shaking until a clear solution is obtamed ca. 1 hour), and then for a further hour to ensure the completeness of the reaction. Remove the complete assembly from the water bath, allow it to cool (observe the formation of crystals), and finally cool in ice. Collect the succinic anhydride as in Method A. The yield is 45 g., m.p. 119-120°. [Pg.375]

Dissolve 57 g. of dry malonic acid in 92 5 ml. of dry P3rridine contained in a 500 ml. round-bottomed flask, cool the solution in ice, and add 57 g. (70 ml.) of freshly distilled n-heptaldehyde (oenanthol) with stirring or vigorous shaking. After a part of the aldehyde has been added, the mixture rapidly seta to a mass of crystals. Insert a cotton wool (or calcium chloride) tube into the mouth of the flask and allow the mixture to stand at room temperature for 60 hours with frequent shaking. Finally, warm the mixture on a water bath until the evolution of carbon dioxide ceases (about 8 hours) and then pour into an equal volume of water. Separate the oily layer and shake it with 150 ml. of 25 per cent hydrochloric acid to remove pyridine. Dissolve the product in benzene, wash with water, dry with anhydrous magnesium sulphate, and distil under reduced pressure. Collect the ap-nonenoic acid at 130-13272 mm. The yield is 62 g. [Pg.466]

Boil a mixture of 10 g. (10 ml.) of o-toluidine and 38 g. (35 ml.) of acetic anhydride in a 75 or 100 ml. Claisen flask fitted with a reflux condenser (Fig. Ill, 28, 1, but with trap replaced by a calcium chloride or cotton wool guard tube) for 1 hour. Arrange the flask for distillation under reduced pressure (compare Fig. II, 20, 1) and distil acetic acid and the excess of acetic anhydride pass over first, followed by the diacetyl derivative at 152-153°/20 mm, some mono-acetyl-o-toluidine (1-2 g.) remains in the flask. The yield of diacetyl-o-toluidine is 14-15 g, it is a colourless, somewhat unstable hquid, which slowly sohdifies to yield crystals, m.p. 18°, To prepare the (mono-) acetyl-o-toluidine, warm a mixture of 5 g. [Pg.578]

To prepare crystalline monoperphthalic acid, place the thoroughly dry ethereal solution (4) in a distilling flask equipped with a capillary tube connected with a calcium chloride or cotton wool drying tube, and attach the flask to a water pump. Evaporate the ether without the application of heat (ice will form on the flask) to a thin syrup (about 150 ml.). Transfer the syrup to an evaporating dish, rinse the flask with a little anhydrous ether, and add the rinsings to the syrup. Evaporate the remainder of the ether in a vacuum desiccator over concentrated sulphuric acid about 30 g. of monoperphthalic acid, m.p. 110° (decomp.), is obtained. [Pg.810]

Acrylic acid polymers Acrylic adhesives Acrylic anhydride Acrylic copolymer Acrylic-cotton blends Acrylic elastomers... [Pg.12]


See other pages where Cotton acids is mentioned: [Pg.53]    [Pg.53]    [Pg.49]    [Pg.87]    [Pg.87]    [Pg.234]    [Pg.287]    [Pg.391]    [Pg.409]    [Pg.27]    [Pg.499]    [Pg.166]    [Pg.189]    [Pg.237]    [Pg.259]    [Pg.278]    [Pg.287]    [Pg.291]    [Pg.312]    [Pg.325]    [Pg.382]    [Pg.389]    [Pg.415]    [Pg.429]    [Pg.712]    [Pg.740]    [Pg.769]    [Pg.791]    [Pg.792]    [Pg.830]    [Pg.857]    [Pg.865]    [Pg.875]    [Pg.962]    [Pg.963]    [Pg.1011]    [Pg.149]    [Pg.868]    [Pg.1]    [Pg.441]    [Pg.514]    [Pg.13]   
See also in sourсe #XX -- [ Pg.348 ]




SEARCH



Acid hydrolysis of cotton

Boric acid cotton-batting

Cotton inorganic acid esters

Cotton mineral acids

Cotton organic acids

Glutamic acid Cotton effects

© 2024 chempedia.info