Potassium carbonate, alcohol oxidation

Poly(vinylferrocenium perchlorate). Hydroperoxide biosensor, 688 POM (polyoxometaUates), 429-30, 1057 POP (persistent organic pollutants), 747 Poppyseed oil, vibrational spectra, 692 Porphyrin, O NMR spectroscopy, 185 Potassium carbonate, alcohol oxidation, 492 Potassium hexacyanoferrate(II), hydrogen peroxide biosensor, 653 Potassium hydrogen phthalate hemiperhydrate, 98-100... 

Fit a 750 ml. round-bottomed flask with a fractionating column attached to a condenser set for downward distillation. Place 500 g. of diacetone alcohol (the crude product is quite satisfactory), 01 g. of iodine and a few fragments of porous porcelain in the flask. Distil slowly. with a small free flame (best in an air bath) and collect the following fractions (a) 56-80° (acetone and a little mesityl oxide) (6) 80-126° (two layers, water and mesityl oxide) and (c) 126-131° (mesityl oxide). Whilst fraction (c) is distilling, separate the water from fraction (6), dry with anhydrous potassium carbonate or anhydrous magnesium sulphate, and fractionate from a small flask collect the mesityl oxide at 126-131°. The yield is about 400 g. 

In a 1 litre round-bottomed flask, equipped with an air condenser, place a mixture of 44 g. of o-chlorobenzoic acid (Section IV,157) (1), 156 g. (153 ml.) of redistilled aniline, 41 g. of anhydrous potassium carbonate and 1 g. of cupric oxide. Reflux the mixture in an oil bath for 2 hours. Allow to cool. Remove the excess of aniline by steam distillation and add 20 g. of decolourising carbon to the brown residual solution. Boil the mixture for 15 minutes, and filter at the pump. Add the filtrate with stirring to a mixture of 30 ml. of concentrated hydrochloric acid and 60 ml. of water, and allow to cool. Filter off the precipitated acid with suction, and dry to constant weight upon filter paper in the air. The yield of iV-phenylanthranilic acid, m.p. 181-182° (capillary tube placed in preheated bath at 170°), is 50 g. This acid is pure enough for most purposes. It may be recrystaUised as follows dissolve 5 g. of the acid in either 25 ml. of alcohol or in 10 ml. of acetic acid, and add 5 ml. of hot water m.p. 182-183°. 

This is followed by hydrolysi.s of the ester moieties with potassium carbonate and reesterification of the carboxy moiety with diazomethane to produce intermediate 65. The solitary free alcoholic hydroxyl at C-9 is oxidized with Collins reagent and the silyl ether groups are removed with acetic acid to give enprostil (63) [15]. 

Nitrocyclohexadiene 93a reacted with 4.0 equivalents of cyclopentadiene in toluene at 110°C for 96 h, producing the 10-glyco-l-nitrotricyclo[5.2.2.02,6]undeca-3,8-diene 96a in 70% yield. Subsequent treatment with potassium carbonate in a methanol-water (9 1) solution followed by oxidative cleavage of the sugar side chain with sodium metaperiodate afforded aldehyde 96c. Reduction of the aldehyde with sodium borohydride produced alcohol 96d. 

Acetals Acids (organic) Acyl halides Alcohols Potassium carbonate Calcium sulphate, magnesium sulphate, sodium sulphate. Magnesium sulphate, sodium sulphate. Calcium oxide, calcium sulphate, magnesium sulphate, potassium carbonate, followed by magnesium and iodine. 

The alcohol may be made practically anhydrous by refluxing with successive portions of fused potassium carbonate until no further action is observed. The carbonate will remain finely divided and will not become sticky when water is absent. A considerable amount of allyl alcohol is lost mechanically during the drying in this way, so that the potassium carbonate which is used here should be employed for the salting out of fresh portions of allyl alcohol in the first part of subsequent preparations. The allyl alcohol thus produced is dry enough for all practical purposes (98-99 per cent) and it is unnecessary to dry with lime or barium oxide as advised in the literature in order to remove all of the water. The allyl alcohol obtained by this process boils at 94-97°-... 

Nitric acid is usually monobasic, forming a series of salts, the nitrates. The basic salts have been discussed by A. Ditte,11 E. Groschuff, and others—see, for example, the basic lead nitrates. The nitrates are usually made by the action of the acid on the metal, hydroxide, oxide, carbonate, etc. According to H. Braconnot, the cone, acid does not decompose dehydrated sodium, barium, calcium, or lead carbonate, even when boiling, because the nitrates of these bases are insoluble in the cone, acid, and a surface film of nitrate protects the remainder of the carbonate from the acid. Potassium carbonate is decomposed by the cone, acid because the nitrate is soluble in the cone. acid. J. Pelouze said that an alcoholic soln. of nitric acid does not act on potassium carbonate, but it acts slowly on sodium, barium, and magnesium carbonates, and rapidly on calcium and strontium carbonates because, added H. Braconnot, calcium and strontium nitrates are readily dissolved by alcohol, whereas potassium nitrate is but sparingly soluble in that menstruum. Potassium hydroxide resists attack by a soln. of nitric acid in ether unless the mixture is boiled or shaken. A. A. Kazantzeff discussed the influence of nitric acid on the solubilities of the nitrates. 

Either amine oxides (usually NMO) [11,26] or potassium ferricyanide/potassium carbonate [12,35] are used as cooxidants for catalytic AD. The choice of oxidant carries with it the choice of solvent for the reaction, and the details of the catalytic cycle appear to be quite different depending on which oxidant-solvent combination is used. When potassium fenicyanide/potas-sium carbonate is used as the oxidant, the solvent used for the reaction is a 1 1 mixture of i-butyl alcohol and water [35,36], This solvent mixture, normally miscible, separates into two liquid phases upon addition of the inorganic reagents. The sequence of reactions summarized below in Eqs, 6D.1-6D.5 has been postulated as occurring under these conditions. This reaction sequence is further illustrated in the reaction cycle shown in Scheme 6D.2, which also emphasizes the role of the two-phase solvent system. 

Complex polyfunctional molecules can often be assembled efficiently by short, spectacular sequences of reactions, an example of which is the preparation of the pentasubstituted benzofuran 1. Thus, addition of l-lithio-l-methoxy-3-(trimethylsilyl)-l,2-hexadiene to 3,4-dimethoxycyclobut-3-ene-l,2-dione gave the expected keto alcohol in 70% yield. This alcohol was heated at reflux temperature in toluene for 4 hours to give a 2,3,5,6-tetrasubstituted hydroquinone in 90% yield. Oxidation of the hydroquinone with silver oxide and potassium carbonate in anhydrous benzene (90%) followed by reaction of the quinone thus obtained with TFA in methylene chloride at 0°C then at room temperature for two days gave 1 in 75% yield. 

Alcohols Anhydrous potassium carbonate anhydrous calcium sulphate or magnesium sulphate calcium oxide. 

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