2- succinic anhydride

Two hundred and thirty-six grams (2 moles) of succinic acid (Note 1) and 153.5 S- (1 mole) of phosphorus oxychloride are placed in a i-l. Claisen flask which is equipped with a reflux condenser, the other openings being stopped with corks. To prevent the escape of fumes into the air, a tube leading to a beaker of water is connected to the open end of the condenser. 

The mixture is heated (Note 2) with a free flame for about fifty minutes until no more hydrogen chloride is evolved. The condenser is then removed, and the flask arranged for distillation. A tube leading to the drain is placed on the side-arm of the receiving flask to carry off the vapors. A few cubic centimeters are collected before the temperature rises to 2550, at which temperature the receiver is changed and the succinic anhydride collected from 255-260° (Note 3). The yield of product melting at 118-120° is 164-192 g. (82-96 per cent of the theoretical amount). 

The crude succinic anhydride may be recrystallized from acetic anhydride 50 g. is added to 35 cc. of acetic anhydride, heated until dissolved and then cooled in an ice bath. The crystals are filtered with suction, washed with two 20-cc. por- 

Succinic acid having a melting point of 189-1900 was used. Less pure material gives a lower-melting product. 

The reaction foams considerably at the start, hence slow and careful heating is necessary. It is best to heat the flask directly with the flame, making certain that all parts of the mixture arc heated about equally. 

Method A. In a 500 ml. round-bottomed flask, fitted with a reflux condenser attached to a gas trap (Fig. II, 13, 8), place 59 g. of succinic acid and 117-5 g. (107-5 ml.) of redistilled acetyl chloride. Reflux the mixture gently upon a water bath until all the acid dissolves (1-2 hours). Allow the solution to cool undisturbed and finally cool in ice. Collect the succinic anhydride, which separates in beautiful crystals, on a Buchner or sintered glass funnel, wash it with two 40 ml. portions of anhydrous ether, and dry in a vacuum desiccator. The yield of succinic anhydride, m.p. 118-119°, is 47 g. 

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°. 

Mix 100 g. of maleic acid (Section 111,143) and 100 ml. of tetra chloroethane in a 250 ml. Claisen or distilling flask provided with a thermometer, and attach a Pyrex Liebig condenser. Heat the flask in an air bath (Fig. 11, 5, 3) and collect the distillate in a measuring cylinder. When the temperature reaches 160°, 76 ml. of tetrachloroethane and 15-15-5 ml. of water are present in the receiver. Empty the water in the condenser and continue the distillation change the receiver when the temperature reaches 190°. Collect the maleic anhydride at 195-197°. Recrystallise the crude anhydride from chloroform. The yield of pure maleic anhydride, m.p. 54°, is 70 g. 

Carry out the following simple experiments with acetic anhydride (compare Section 111,89). 

Perform the following experiment with succinic anhydride. This illustrates the formation of an anilic acid, which is usually an excellent 

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H02C(CH2)2C02H. Colourless prisms m.p. 182 C, b.p. 235°C. Occurs in amber, algae, lichens, sugar cane, beets and other plants, and is formed during the fermentation of sugar, tartrates, malates and other substances by a variety of yeasts, moulds and bacteria. Manufactured by the catalytic reduction of maleic acid or by heating 1,2-dicyanoethane with acids or alkalis. Forms an anhydride when heated at 235°C. Forms both acid and neutral salts and esters. Used in the manufacture of succinic anhydride and of polyesters with polyols. 

The polyispbptylenes (PIB) having molecular weights ranging from 1000 to 2000 are substituted by maleic anhydride, and the polyisobutylene succinic anhydride (PIBSA) formed is neutralized by a polyethylene-polyamine as indicated in Figure 9.10. 

Benzoic acid Succinic. anhydride Hexacetyl mannitol ... 

In the following preparation, this reaction is exemplified by the union of anthracene with maleic anhydride, to form 9,io-dihydroanthracene-9,io-e do-a -succinic anhydride note that as a result of this reaction both the outer rings of the anthracene system become truly aromatic in character. 

B) Acetic, succinic anhydride phthalic anhydride (and substituted derivatives). 

To distinguish these anhydrides from the corresponding acids, note that succinic anhydride (m.p. 120°) is almost insoluble in cold water, whereas succinic acid (m.p. 185 ) is readily soluble. Phthalic anhydride has m.p. 132° and phthalic acid has m.p. 196-199° with decomposition. Each of these anhydrides when heated with water hydrolyses to the corresponding acids. 

The fluorescein test for succinic acid (p. 349) and the phthalein and fluorescein tests for phthalic acid (p. 351) are obviously given also by succinic anhydride and phthalic anhydride, as these tests depend upon the initial formation of the anhy dride in each case. 

A further example is given below illustrating the use of a dibasic anhydride (succinic anhydride) the succinoylation reaction is a valuable one since it leads to aroyl carboxylic acids and ultimately to polynuclear hydrocarbons. This general scheme of synthesis of substituted hydrocarbons through the use of succinic anhydride is sometimes called the Haworth reaction. Thus a-tetralone (see below) may be reduced by the Clemmensen method to tetralin (tetrahydronaphthalene) and the latter converted into naphthalene either catal3d.ically or by means of sulphur or selenium (compare Section, VI,33). 

The preparation of the cyclic ketone a-tetralone possesses a number of interesting features. Succinic anhydride is condensed with pure benzene in the presence of anhydrous aluminium chloride (slightly over two equivalents see 1 above) to yield (3-benzoylpropionlc acid ... 

Anthracene and maleic anhydride. In a 50 ml. round-bottomed flask fitted with a reflux condenser, place 2 0 g. of pure anthracene, I 1 g. of maleic anhydride (Section 111,93) and 25 ml. of dry xylene. Boil the mixture under reflux for 20 minutes with frequent shaking during the first 10 minutes. Allow to cool somewhat, add 0 5 g. of decolourising carbon and boil for a further 5 minutes. Filter the hot solution through a small, preheated Buchner funnel. Collect the solid which separates upon coohng by suction filtration, and dry it in a vacuum desiccator containing paraffin wax shavings (to absorb traces of xylene). The yield of adduct (colourless crystals), m.p. 262-263° (decomp.), is 2-2 g. Place the product (9 10-dihydroanthracene-9 10-cndo-ap-succinic anhydride) in a weU-stoppered tube, since exposure to air tends to cause hydration of the anhydride portion of the molecule. 

Supplement (combined with Volumes XVIII and XIX) XVII, 2nd 1934 2359-3031 Hydroxy compounds Furfuryl alcohol, 112. Carbonyl compounds Butyrolactone, 234. Furfural, 272. 2-Aoetyl-thio-phene, 287. Xanfhone, 366. Succinic anhydride, 404. Phthalio anhydride, 469. 

It will be easy to put in bond a because it is para to the MeO group, but bond b might be difficult Tire strategy is to put in bond a first and use an intramolecular reaction to force bond b to go in the right place. Succinic anhydride is a convenient four carbon electrophile ... 

Succinic anhydride the structure of which is shown is a cyclic... 

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