DE1670295A1 - Process for the preparation of 4,4,5,5-tetrahalopyridazone- (6) - Google Patents

Description

Process for the preparation of 4,4,5,5-tetrahalopyridazone- (6) This invention relates to a process for the preparation of 4,4,5,5-tetrahalopyridazones by reacting Oxodihalogenpyridazinonen- (6) with inorganic acid halides Acids.

It has been found that 4,4,5,5-Tetrahalogenpyridazone- (6) of the general formula where R1 and R2 can be the same or different and each denotes hydrogen, an aliphatic, cycloaliphatic, araliphatic or aromatic radical, R1 also denotes a heterocyclic radical and R2 also denotes halogen, a nitro or alkoxy group and X denotes halogen, @ advantageous obtained when 4-oxo-5,5-dihalogenpyridazinone- (6) of the general formula where R1 and R2 have the aforementioned meaning and the pair of radicals R3 denotes two halogen atoms, are reacted with halides of phosphoric acid, phosphorous acid, sulfuric acid, sulfurous acid or carbonic acid.

If 1-methyl-3-phenyl-4-oxo-5,5-dichloro-pyridazinone- (6) and phosphorus pentachloride are used, the reaction can be represented by the following formulas: The process according to the invention provides a large number of the hitherto unknown #, 4,5,5-Tetrahalogenpyridazinone- (6) in a simple way in good yield and. Purity. These advantageous results are achieved without substantial formation of by-products, e.g. 4,5-dihalopyridazones, 3,4,5-trähalopyridazones. The starting materials used are pyridazinone (6) derivatives of the general formula TI, which, for example, according to: in patent. ..:. ..: (Patent application H 94 355 IVd / 12 p) described processes can be produced. Preferred starting materials II and correspondingly preferred end materials I are those in the form of which R1 and: R2 can be the same or different and in each case R1 also denotes hydrogen, an alkyl, cycloalkyl, aralkyl or aryl radical with in particular up to 12 carbon atoms in each case a heterocyclic 5- or 6-membered ring bonded via a carbon atom, which can contain one or two nitrogen atoms, one oxygen and / or one sulfur atom, and R2 also bromine, iodine or, in particular, chlorine, a nitro or alkoxy group with up to 7 carbon atoms, and X stands for bromine or especially chlorine. The preferred starting materials II are 4-oxo-5,5 = dihalogenpyridazinone- (6), in which the halogen is bromine or, in particular, chlorine. For example, 8. The following pyridazinones II are used as starting materials: 1-methyl-, 1-cyclohexyl-, 1-benzyl-, 1-phenyl-, 1-toluyl-, 1-pyridyl- (2 °) -, 1-tetrahydrofurfuryl-4-oxo --5,5-dichloropyridazinone- (6-) and corresponding compounds substituted in the 3-position; 1-ethyl-3-chloro-, 1-naphthyl-3-ethoxy-, 1-isobuty1-3-phenyl-, 1-phenyl-3-b.om-, 1-pyridazinyl- (6) -4-oxo- `.), 5-dichloro-pyrdazinrne- (6); analog 5.5 dibromo compounds. The pyridazinones II are: implemented according to the process of the invention with halides of phosphoric acid, phosphorous acid, sulfuric acid, sulfurous acid or carbonic acid or their mixtures. Preferred halides are bromides, iodides or, in particular, chlorides, for example phosphorus pentachloride, bromide, todide, phosphorus trichloride, bromide, iodine, phosphorus oxycharide, thionyl chloride, sulfuryl chloride, sulfuryibromide or phosgene. You can use the halides in stoichiometric 'amount or irr. Use excess, preferably one to ten times: excess, based on starting material II: The reaction is generally carried out at a temperature between 0 and 150 ° C., preferably between 60 and 120 ° C., without pressure or under pressure, continuously or batchwise. It is advantageous to use tertiary amines or N, N-disubstituted acid amides in the reaction - z-.B. Triethylamine, dimethylaniline, diethylaniline, pyridine, dimethylformamide, N-methylpyrrolidone, tetramethylurea, generally in an amount of 100 to 1,000 percent by weight, based on starting material II Solvent for the starting material II.

But you can also additionally under the reaction conditions inert, organic solvents or diluents such as chlorinated hydrocarbons, e.g. methylene chloride, carbon tetrachloride, chlorobenzene or aromatic hydrocarbons, z: B. Use benzene, toluene, nitrobenzene. The reaction can be carried out as follows be: A mixture of starting material II, acid halide and-optionally-tertiary Amine, acid amide and / or solvent is mixed well for 1 to 4 hours held at the reaction temperature. Then the more volatile components of the mixture, especially the acid halide, distilled off: The residue is decomposed by the addition of ice, using a diluent beforehand if necessary can be added. The crystallized end product is separated off by filtration: Optionally, the end product can also be recrystallized from cyclohexane or Petroleum ether to be purified: Those producible by the method of the invention new compounds are flame retardants, stabilizers for halogen-containing - plastics and rubbers and valuable raw materials for the production of these Aids used and dyes. So you can with them e.g. in an amount of 50 to 200 grams, based on: one kilogram of fiber material, Impregnate in a solution in ethyl acetate cotton fabric, dry at 50 to 900C and thus obtain flame-resistant fabrics that do not glow afterwards. Handle or shade of the tissue are practically not affected.

The parts mentioned in the examples are parts by weight. Example 1 25.7 parts of 1-phenyl-4-oxo-5,5-dichloro-pyri-dazinon- (6) and 300 parts of phosphorus oxychloride are heated to 70 ° C. with stirring. At 60 to 70 ° C., 42 parts of phosphorus pentachloride are added in portions and the mixture is then heated for a further hour. to simmer. Most of the excess phosphorus oxychloride is now distilled off and the remaining syrupy residue is decomposed with ice. 29.5 parts (corresponds to 94; 5% of theory) of a white substance which - recrystallized from cyclohexane - melts at 85 to 870 ° C. crystallize. 1-phenyl-4,4,5,5-tetrachloro-pyridazinone- (6) Analysis: C10H60N2C14 (MG 312) calculated: C 38.45 % H 1.923% 0 5.13% N 8.97% C1 45.5% found: - C 39.1% H 2.0% 0 5.2% N 9.0 % C1 44 ";%. Example 2 27.1 parts of 1-methyl-3-phenyl-4-oxo-5,5-dichloro-pyridazinone- (6) result analogously to Example 1 with equal amounts of phosphorus oxychloride and phosphorus pentachloride after the excess phosphorus oxychloride has been distilled off and the decomposition Residue with ice 28 parts (corresponds to 86% of theory) 1-methyl-3-phenyl-4,4,5,3-tetrachloropyridazinone- (6), which - recrystallized from cyclohexane - melts at 138 to 1400C. Analysis: C11H80N2c14 (MG 326) Calculated: C 40.5% H 2.455% 0 4.91% N 8.59% Cl 43.55 found: C 40.6% H 2.6% 0 59®% N 8.9 % C1 42.9%. Example 3 11 parts of 1-cyclooctyl-4-oxo-5,5-dichloropyridazinone- (6) are suspended in 170 parts of phosphorus oxychloride. With stirring, 16 parts of phosphorus pentachloride are added at 60 ° to 70 ° C. and the mixture is kept boiling for 4 hours. After distilling off the phosphorus oxychloride and decomposing the residue with ice as in Example 1, 10 parts (corresponds to 76.5% of theory) of 1-cyelooctyl-44,5,5-tetrachloropyridazinone (6) are obtained. Recrystallized from petroleum ether, the end product has a melting point of 70 to 720C. Analysis: C12H160N2C14 (MG 346 - Calculated: C 41.6% H 4.625% 0 4.62: 5% N 8.1%. C1 41.05 Found: C 42.2% H 4.7% 0 5.0% N 8.2% Cl 40.3%. Example 4 25 parts of 1-methyl-4-oxo-5,5-dichloropyridazinone- (6) are heated in 330 parts of phosphorus oxychloride to 70 ° C. with stirring. At 60 to 70 ° C., 30 parts of phosphorus pentachloride are added in portions and the mixture is then refluxed for 4 hours. The excess phosphorus oxychloride is stripped off in vacuo and the residue is decomposed with ice. 29 parts are obtained (corresponds to 90.6% of theory) of 1-methyl-4,4,5,5-tetrachloropyridazinone- (6) which, recrystallized from petroleum ether, melts at 60 to 620C =. Analysis: C5H40N2CT4 (MG 250) Calculated: C 24.0% H 1.6% 0 6.4% N 11.2% C1 56.8 Found: C 24.7 y6 H 1.8% O 6.7 % N 109% C1 56.1

Claims (1)

Claims l. @-Process for the preparation of 4,4,5,5-Tetrahalogenpyridazonender general formula where R1 and R2 can be the same or different and each signify hydrogen, an aliphatic, eycloaliphatic, araliphatic or aromatic radical, R1 furthermore also a heterocyclic radical and R2 also halogen,. may denote a nitro or alkoxy group, and X represents halogen, characterized in that 4-oxo-5,5-dihalo-6-pyridazinones) of the general formula where R1 and R2 have the aforementioned meaning and the pair of radicals R3 denotes two halogen atoms, is reacted with halides of phosphoric acid, phosphorous acid, sulfuric acid, sulfurous acid or carbonic acid. 4,4,5,5-Tetrahalogenpyridazone- (6) of the general formula where R1 and R2 can be identical or different and each denotes hydrogen, an aliphatic, eycloaliphatic, araliphatic or aromatic radical, and R1 is beyond that. also a heterocyclic radical and R2 can also denote halogen, a nitro or alkoxy group and X stands for halogen. -