| 摘要 |
Halogenated a -naphthoyl-o-benzoic acids containing the halogen in the 5<1>- or both the 5<1>- and 8<1>-positions of the naphthalene ring are produced by direct halogenation of a -naphthoyl-o-benzoic acid preferably dissolved in acetic acid. Other solvents and halogenating agents such as thionyl chloride may be used, but sulphuric acid, if used, tends to give the dihalogen derivative directly. The 5<1>-halogeno-1<1>-naphthoyl-2-benzoic acid produced may be nitrated to give the 5<1>-halogeno-8<1>-nitro- or the 5<1>-8<1>-dinitro-1<1>-naphthoyl-2-benzoic acid. In examples, (1) a -naphthoyl-o-benzoic acid is brominated in the presence of glacial acetic acid to give the 5<1>-bromo derivative. By fusion with caustic alkali, the product yields 5-hydroxy-1-naphthoic acid or when cyclised with concentrated sulphuric acid in the presence or absence of boric acid it yields a a b z - monobromobenzanthraquinone. (2) a - Naphthoyl-o-benzoic acid is dibrominated in the presence of ferric chloride and iron powder to give the 5<1>-8<1>-dibromo derivative which when cyclised with concentrated sulphuric acid in the presence or absence of boric acid yield a dibromobenzanthraquinone. (3) a -Naphthoyl-o-benzoic acid is brominated in the presence of ferric chloride to give a product identical with that of example 2. (4) a -Naphthoyl-o-benzoic acid is chlorinated in the presence of glacial acetic acid to yield 5<1>-chloro-1<1>-naphthoyl-2-benzoic acid. A b z-chloro-benzanthraquinone compound is obtained by cyclisation with sulphuric acid in the presence or absence of boric acid. (5) a -Naphthoyl-o-benzoic acid is chlorinated in the presence of sulphuric acid to obtain 5<1>-8<1>-dichloro-1<1>-naphthoyl-2-benzoic which may then be cyclised by means of sulphuric acid and benzoic acid to a mixture of two dichlorobenzanthrones which may be separated by fractional crystallisation. (6) 5<1> - bromo - 1<1> - naphthoyl - 2 - benzoic acid is dissolved in sulphuric acid and nitrated with a mixture of nitric and sulphuric acids to give the 8<1>-nitro compound. The nitro-compound may be reduced with iron and acid to give a pyrrole. (7) 5<1>-Chloro-1<1>-naphthoyl-2-benzoic is similarly nitrated to the 8<1>-nitro compound. (8) A solution of 5<1>-bromo-1<1>-naphthoyl-2-benzoic acid in acetic anhydride is treated with nitric acid to obtain the 5<1>-8<1>-dinitro compound. The acids may, in all cases, be neutralised with caustic soda to give the sodium salt.
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