| 摘要 |
1443620 Naphthyridine and quinoline derivatives by ring-closure DYNAMIT-NOBEL AG 28 Aug 1974 [29 Aug 1973] 37693/74 Heading C2C A process for the preparation of a cyclisate comprises effecting, in an organic solvent, a ring-closure reaction of a compound capable of undergoing such a reaction when heated in the solvent, wherein the compound, either in the form of a melt or in the form of a solution in an organic solvent, is brought to the temperature required for the ring-closure reaction by being mixed with a quantity of pre-heated organic solvent, the quantity and temperature of the pre-heated solvent being such that the resulting reaction mixture has the temperature required for the ring-closure reaction. The ring-closure reaction is preferably effected at a temperature of from 200‹ to 360‹ C. with the solvent being pre-heated to a temperature of from 240‹ to 360‹ C. Suitable solvents include diphenylbenzene, dibenzylbenzene, ditolyl, diphenylethane, triphenylmethane, tetraphenylmethane, benzophenone, and terephthalic acid dimethyl ester. Following the ring-closure reaction, the reaction mixture is suitably quenched by passage through a heat exchanger or by the introduction into a low-boiling solvent. Examples describe the preparation of 4-hydroxy-3- carbalkoxy - naphthyridines and quinolines, which may be further substituted, from the corresponding pyridyl- and phenyl-aminomethylene malonic acid ester, and compounds having the general formula wherein R 1 is N or CH, R 2 and R 5 are alkyl groups, R 3 and R 4 are alkyl or alkoxy groups or halogen atoms or together represent an group, and R 6 is hydrogen or alkyl from a compound of the formula |
