Synthesis Of Chloropyridazines Deriratives

Pyridazine derivatives do not appear to occur in natural products, and also have been relatively neglected in the investigation of potential pharmaceuticals. Some pyridazines have been examined for activity against sporozoan, and flagellate parasites and for antiamebic activity. Pyridazinone derivatives have been applied in field of pharmacy and agricultural chemicals due to their wide range of versatile, significant bioactivities and pharmalogical activities. In recent years synthetic work on pyridazinone derivatives have been become hotter in synthetic chemistry. Many pyridazinones exhibited inhibition of platelet aggregation and treat congestive heart failure activities. In the same time, they were well-known compounds in agrochemical research, such as insecticides, acaridcides and show higher bioactivity against tobacco mosaic virus (TMV) etc. The heterocyclic compounds with 1,3-thiazolidinone, 1,3,4-oxadiazoline, and 1,2,4-triazole had significant biological activities as fungicides, insecticides, micribiocides, bactericides, anticunvulsants, antiviral, antibacterial etc. The synthesis of heterocycle and their biological activities are gradually becoming a hot thesis in heterocyclic chemistry. Especially, the compounds with pharmalogical activities became the most active field in new heterocyclic synthesis. In view of those observation and expect to realize the inforcement of many physiological activities by means of combining pyridazinone with different heterocycles. The heterocyclic compounds were unreported. The structure of intermediated and target compounds were conformed by elemental analysis, 1H NMR, IR and MS spectral date. This thesis is composed of the follows. 1: Hydrazides of pyridazinone were prepared from the starting materials α-ketoglutaric acid and hydrazine hydrate. The reaction of carboxylic hydrazides with aromatic aldehydes afforded carbonyl aromatic aldehyde hydrazones of pyridazinone. 1,3,4-Oxadiazolines were obtained by cyclization of 6-pyridazinone-3-carbonyl aromatic aldehyde hydrazones with acetic anhydride. 2: carbonyl aromatic aldehyde hydrazones of pyridazinone reacted with mercaptoacetic acid obtained the 1,3-thiazolidinone derivatives. 3: Chloro compounds reacted with substituted carboxylic hydrazide can obtain pyridazino [3,2-c]-1,2,4-triazole. The innovations of the thesis are based on the follows: 1. 1,6-dihydro (or 1,4,5,6-tetrahydro)-6-pyridazinone-3-carboxylic hydrazides reacted with aromatic aldehydes can afford 1,6-dihydro (or 1,4,5,6-tetrahydro )-6-pyridazinone-3-carbonyl aromatic aldehyde hydrazones; 2. carbonyl aromatic aldehyde hydrazones cyclized with acetic anhydride can obtain 2-aryl-3-[1,6-dihydro(or1,4,5,6tetrahydro)-6-pyridazinone-3-yl] -4,5-dihydro -1,3,4-oxadiazole; 3. carbonyl aromatic aldehyde hydrazones reacted with mercaptoacetic acid can obtain 2-aryl -3-[(or 1,6-dihydro) 1,4,5,6 -tetrahydro-6-pyridazinon -3-yl-carbonylamino]-4-thiazolidinone; 4. pyridazino [3,2-c]-1,2,4-triazoles can be obtained through cyclizing of 3-aryl-6-chloro...