Action of Carbon Dioxide on Sodium Acetylides in Dry Ether

Reaction XXXIV. (c) Action of Carbon Dioxide on Sodium Acetylides in Dry Ether. (B., 12, 853 J. pr., [2], 27, 417 B., 33, 3586.)—This is an example of the great activating influence of a triple bond. When carbon dioxide is passed into a solution of the sodium derivative of an acetylenic hydrocarbon in dry ether, direct addition takes place to give the sodium salt of the next highest acetylenic carboxylic acid. For example, sodium allylene yields sodium tetrolate— 

CHSC j CNa— CHS.C i C.COONa, and sodium phenyl-acetylene gives sodium phenyl-propiolate— 

This reaction should be compared with the preceding one. It should be noted that the presence of a triple bond attached to a carbon makes a hydrogen attached to that carbon replaceable by a metal (cf. Reaction XXIII. (a)). 

Reaction XXXV. (a) Condensation of Phthalic Anhydride with Aromatic Hydrocarbons in the presence of Anhydrous Aluminium Chloride 

The oriAo-benzoyl-benzoic acids readily yield anthraquinone and its derivatives (see p. 82). It may be noted that o-benzoyl-benzoic acid itself, with benzene and aluminium chloride, yields phthalophenone the same compound is made directly from phthalic anhydride by increasing the amount of the latter or by adding acetic anhydride. The same holds for p-toluoylbenzoic acid and ditoluoylphthalide. (Am. Soc., 43, 1965 J. C. S., 122, 539.) (For the use of carbomethoxylbenzoyl chlorides and of homophthalic anhydrides in these reactions, see Am. Soc., 43, 1950.) 

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