Patent GB-335948-A (GB)
Title: Improvements in the halogenation of isocyclic compounds
IPC: C07C17/12
Filed: 1929-04-03
Abstract: 335,948. Johnson, J. Y., (I. G. Farbenindustrie Akt.-Ges.). April 3, 1929. Samples furnished. Halogenated isocyclic compounds. - Isocyclic compounds substituted in the nucleus by chlorine or bromine or both halogens are prepared by acting on isocyclic compounds with hydrochloric or hydrobromic acid or both these acids in oleum or chlorsulphonic, or mixtures thereof, in the presence of halogen carriers. The halogen hydrides may be formed in situ by adding salts such as sodium chloride or bromide, and both halogens may be introduced into the molecule in one operation by using the two acids or a mixture of acid and alkali metal salt. Suitable halogen carriers are sulphur, iodine, antimony, arsenic, bismuth, mercury and compounds thereof, and they may be used in amounts up to about 10 per cent of the substance to be halogenated. The working temperature varies with the substance to be halogenated and is also influenced by the amount and kind of catalyst present; thus lower temperatures may be employed with larger amounts of catalyst present, or when the latter are non-metallic; higher temperatures are required when oleum of low sulphur-trioxide content is used as the diluent. Temperature conditions may be chosen to avoid or favour side-reactions, and thus may be prepared halogenated-sulphonic acids, for example, chlornaphthalene sulphonic acid, or halogenated quinones from hydrocarbons, for example bromoperylene-quinone. Both hydroaromatic and aromatic compounds may be halogenated, suitable compounds mentioned being benzene, naphthalene, anthracene, pyrene, perylene and derivatives such as nitro, amino and halogen derivatives; benzanthrones, dibenzanthrones, ms-benzdianthrones, ms-naphthodianthrones, allo-ms-naphthodianthrones, ms-anthradianthrones, anthanthrones, dibenzpyrenequinones or isomeric compounds. In examples, (1) dibenzanthrone is treated in chlorsulphonic acid in presence of antimony (or sulphur, iodine, mercury), with hydrogen bromide; dibromo- and higher brominated derivatives dyeing fast, marine blue shades are obtained. A similar dyestuff is obtained by treatment in chlorsulphonic acid in presence of antimony with potassium bromide, treatment in chlorsulphonic acid in presenoe of iron sulphate and sulphur with dry hydrochloric acid yields a chlordibenzanthrone. All these processes applied to isodibenzanthrone yield bromo- and chloro-derivatives respectively dyeing violet shades : (2) Benzanthrone is treated in chlorsulphonic acid and in presence of iodine, with dry hydrobromic acid to give a bromo derivative: (3) Pyranthrone in chlorsulphonic acid in presence of sulphur is treated with dry hydrobromic acid; di-, tri-, and tetrabromo-derivatives are obtained dyeing orange to orange-red shades. A di- and tetrabromo derivative are also obtained by using potassium bromide instead of the acid vapour. A chlorpyranthrone is obtained by using dry hydrochloric acid instead of hydrobromic acid : (4) 3. 4. 8. 9 dibenzopyrene-5.10-quinone in chlorsulphonic acid (or oleum) and in presence of iodine is treated with dry hydrobromic acid; mono- or higher bromo derivatives dyeing yellow-orange shades are produced. By using potassium bromide instead of the acid vapours a dibromo derivative is obtained. Both methods applied to the 4. 5. 8. 9.-dibenzopyrene-3.10.- quinone yield bromo derivatives dyeing red shades : (5) anthanthrone in oleum is treated with potassium iodide, and the product then treated with potassium bromide; a bromoiodo derivative which may be purified by way of the oxonium sulphate separating from sulphuric acid solution or by recrystallization and which dyes orange-red is obtained. Monomethoxyanthanthrone (obtained by nitrating anthanthrone with 66 per cent nitric acid, reducing, diazotizing, conversion to an hydroxy derivative and methylation of the latter) in chlorsulphonic acid and in presence of iodine is treated with potassium bromide and yields a monobromomonomethoxy derivative dyeing blue-red shades a monochloromonomet,hoxy derivative is obtained in an analogous manner and dyes orange shades. Similar dyestuffs are obtained from other anthanthrone ethers, for example the ethoxy- and w-chlorethoxyanthanthrones the monohalogen monoalkylethers of anthanthrones are stated to be particularly valuable dyestuffs: (6) Toluene in chlorsulphonic acid and in presence of iodine is treated with dry hydrogenbromide to give a bromotoluene; benzene in similar manner yields di-, tetra-, and hexabromo derivatives, and naphthalene, phenanthrene, and hexahydrobenzene can also be brominated in the same way. The treatment of perylene in chlorsulphonic acid and in presence of iodine with hydrobromic acid to give bromoperylenequinone is also mentioned.