Phthalic anhydride, hydrogenation

MC.-Octyl alcohol methyl n-hexyl carbinol CH3CH(OH)(CHj)jCH3 = CgH,OH is converted by heating with phthalic anhydride into sec.-octyl hydrogen phthalate ... 

Place a mixture of 1 0 g. of the hydrocarbon, 10 ml. of dry methylene chloride or ethylene dichloride or syw.-tetrachloroethane, 2 5 g. of powdered anhydrous aluminium chloride and 1-2 g. of pure phthalic anhydride in a 50 ml. round-bottomed flask fitted with a short reflux condenser. Heat on a water bath for 30 minutes (or until no more hydrogen chloride fumes are evolved), and then cool in ice. Add 10 ml. of concentrated hydrochloric acid cautiously and shake the flask gently for 5 min utes. Filter oflf the solid at the pump and wash it with 10-15 ml. of cold water. Boil the resulting crude aroylbenzoic acid with 10 ml. of 2 -5N sodium carbonate solution and 0 2 g. of decolourising carbon for 5 minutes, and filter the hot solution. Cool, add about 10 g. of crushed ice and acidify... 

Monoperphthalic acid. This is obtained by adding finely-powdered phthalic anhydride to a well-stirred solution of 30 per cent, hydrogen peroxide in alkali at —10° the solution is acidified and the per acid is extracted with ether ... 

Paint and varnish manufacturing Resin manufacturing closed reaction vessel Varnish cooldng-open or closed vessels Solvent thinning Acrolein, other aldehydes and fatty acids (odors), phthalic anhydride (sublimed) Ketones, fatty acids, formic acids, acetic acid, glycerine, acrolein, other aldehydes, phenols and terpenes from tall oils, hydrogen sulfide, alkyl sulfide, butyl mercaptan, and thiofen (odors) Olefins, branched-chain aromatics and ketones (odors), solvents Exhaust systems with scrubbers and fume burners Exhaust system with scrubbers and fume burners close-fitting hoods required for open kettles Exhaust system with fume burners... 

A. Preparation of Sec.-Oclyl Hydrogen Phihalate.—A mixture of 130 g. (i mole) of 5ec.-octyl alcohol (Org. Syn. 1, 61) and 148 g. (i mole) of phthalic anhydride is heated for twelve to fifteen hours in a flask surrounded by an oil bath at 110-115° (Note i). During the heating the mixture should be mechanically stirred... 

The checkers performed this step on a smaller scale (ca. f) and noted (proton magnetic resonance spectrum) occasional contamination (up to 10%) by phthalic anhydride. This impurity causes no subsequent difiSculties. Washing of the crude reaction mixture with cold aqueous sodium hydrogen carbonate resulted in serious product loss because of its appreciable solubility in this medium and therefore should be avoided. 

A 500-ml, three-necked, round-bottom flask is fitted with a mechanical stirrer, a thermometer, and a wide-stern (powder) funnel. The flask is cooled in an ice-salt bath and charged with 125 ml (approx. 0.5 mole) of 15% sodium hydroxide solution. When the stirred solution reaches -10°, 30% hydrogen peroxide (57.5 g, 52.5 ml, approx. 0.5 mole) previously cooled to -10° is added in one portion. The pot temperature rises and is allowed to return to —10° whereupon 37.5 g (0.25 mole) of phthalic anhydride (pulverized) is added rapidly with vigorous stirring. Immediately upon dissolution of the anhydride, 125 ml (approx. 0.25 mole) of cooled (-10°) 20% sulfuric acid is added in one portion. (The time interval between dissolution of the anhydride and the addition of the cold sulfuric acid should be minimized.) The solution is filtered through Pyrex wool and extracted with ether (one 250-ml portion followed by three 125-ml portions). The combined ethereal extracts are washed three times with 75-ml portions of 40% aqueous ammonium sulfate and dried over 25 g of anhydrous sodium sulfate for 24 hours under refrigeration. 

Betulol is a sesquiterpene alcohol of the formula CjjH O, found in oil of birch buds. It can be isolated as a hydrogen phthalate, by warming a solution of betulol in benzene, with phthalic anhydride. It has, according to Soden and Elze, the following characters —... 

Phthalic anhydride is reacted with phenylacetic acid to form 3-benzylidenephthalide which is then hydrogenated to 2-phenethylbenzoic acid. Conversion to the acid chloride followed by intramolecular dehydrochlorination yields the ketone, 5H-dibenzo[a,d] cyclohepten-5-one. The ketone undergoes a Grignard reaction with 3-(dimethylamino)propyl chloride to give 5-(7-dimethylaminopropylidene)-5H-dibenzo[a,d] cycloheptene. 

Note that in these three examples involving hydrogen peroxide, chromium trioxide and sodium nitrite, dangerous reactions have been described for carboxyiic acids (see on p.316-317). They all referred to the three following systems acetic acid-/hydrogen peroxide, acetic acid/chromium trioxide and o-phthalic acid/sodium nitrite. One can ask oneself whether the same reactions did not take place after the acetic and phthalic anhydride hydrolysis. 

Phenyl indandiones With an acidic hydrogen often interfere with clot formation. When electron withdrawing groups are present in the p-position, acidity is increased and activity goes up. The opposite effect is seen with electron-donating substituents. Synthesized in the usual way, the anticoagulant bromindione (15) results from sodium acetate-catalyzed condensation of phthalic anhydride and p-a-bromophenyl-acetic acid. ... 

The phthalide used by the submitters and by the checkers was a commercial product, obtained from E. I. du Pont de Nemours and Company, Wilmington, Delaware. This product is no longer available. Phthalide may be prepared in 82.5 per cent yields by hydrogenation of phthalic anhydride in benzene at 270° under 3000 lb. pressure in the presence of copper chromite 1 or, in yields of 61-71 per cent, from phthalimide according to the procedure given in Org. Syn. 16, 71 Coll. Vol. 2, 1943, 526. 

The first examples of a homogeneous reduction of this type were reported in 1971. Cobalt carbonyl was found to reduce anhydrides such as acetic anhydride, succinic anhydride and propionic anhydride to mixtures of aldehydes and acids. However, scant experimental details were recorded [94]. In 1975, Lyons reported that [Ru(PPh3)3Cl2] catalyzes the reduction of succinic and phthalic anhydrides to the lactones y-bulyrolaclone and phthalide, respectively [95], The proposed reaction sequence for phthalic anhydride is shown in Scheme 15.15. Conversion of phthalic anhydride was complete in 21 h at 90 °C, but yielded an equal mixture of the lactone, phthalide (TON = 100 TOF 5) and o-phthalic acid, which is presumably formed by hydrolysis of the anhydride by water during lactoniza-tion. Neither acid or lactone were further hydrogenated to any extent using this catalyst system, under these conditions. 

Succinic anhydride is clearly hydrogenated more readily than the acid, as was the case with phthalic acid (Scheme 15.17), but faster absolute rates were observed in the hydrogenation of o-phthalic acid and phthalic anhydride to phtha-lide. In these reactions, the problem of anhydride hydrolysis is less significant as the acid can also be reduced to the same lactone product... 

In a i-l. round-bottomed flask, equipped with a mechanical stirrer and cooled in an ice-salt bath, is placed 275 g. (250 cc., approximately 1 mole) of 15 per cent sodium hydroxide solution. This is cooled to —10° (Note 1), and 115 g. (105 cc., approximately 1 mole) of 30 per cent hydrogen peroxide which has been similarly cooled is added in one portion. The heat of reaction causes the temperature to rise markedly. When the temperature has again dropped to — io°, 75 g. (0.5 mole) of phthalic anhydride which has been pulverized to pass a 40-mesh sieve is added as quickly as possible while the contents are stirred vigorously in the freezing mixture (Notes 2 and 3). As soon as all the anhydride has dissolved, 250 cc. (0.5 mole) of 20 per cent sulfuric acid which has been previously cooled to — xo°, but not frozen (Note 4), is added. 

Fluidised catalysts are also used in the synthesis of high-grade fuels from mixtures of carbon monoxide and hydrogen, obtained either by coal carbonisation or by partial oxidation of methane. An important application in the chemical industry is the oxidation of naphthalene to phthalic anhydride, as discussed by Riley(131). The kinetics of this reaction are much slower than those of catalytic cracking, and considerable difficulties have been experienced in correctly designing the system. 

Hydrogenation of phthalic anhydride over copper chromite afforded 82.5% yield of the lactone, phthalide, and 9.8% of o-toluic acid resulting from hydrogenolysis of a carbon-oxygen bond [1015]. Homogeneous hydrogenation of a,a-dimethylsuccinic anhydride over tris(triphenylphos-phine)rhodium chloride gave 65% of a,a-dimethyl- and 7% of )S,)S-dimethyl-butyrolactone [1016]. 

So far, no reference has been made to the presence of more than one phase in the reactor. Many important chemicals are manufactured by processes in which gases react on the surface of solid catalysts. Examples include ammonia synthesis, the oxidation of sulphur dioxide to sulphur trioxide, the oxidation of naphthalene to phthalic anhydride and the manufacture of methanol from carbon monoxide and hydrogen. These reactions, and many others, are carried out in tubular reactors containing a fixed bed of catalyst which may be either a single deep bed or a number of parallel tubes packed with catalyst pellets. The latter arrangement is used, for exjimple, in the oxidation of ethene to oxiran (ethylene oxide)... 

Potassium hydrogen phthalate is prepared by neutralization reaction of phthalic anhydride and potassium hydroxide, followed by crystallization ... 

Half neutralization of a phthalic anhydride solution forms potassium hydrogen phthalate. 

For the preparation of [l]benzothieno[3,2- ][l]benzofuran-10,10-dioxide 64, hydrogen peroxide in acetic acid, 3-chloroperoxybenzoic acid, and also the urea-hydrogen peroxide adduct with phthalic anhydride were employed. All three methods provided 64 in excellent yields (88-94%). Monitoring the course of the reaction showed the... 

Among the neutral substrates, alcohols can be easily converted into an acid by forming the hydrogen phthalate with phthalic anhydride. The acid can then be resolved with one of the bases from Table 2. 

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