| 2-chloro-5-methylpyridine is an important intermediate of medicines and insecticides. In this thesis a better technology method for the synthesis of 2-chloro-5-methylpyridine with an overall yield of 64.1% is developed via condensation, acyclation. cyclisation from cheap and easily available benzylamine. The route have some merits as following: cheap and available material, short steps, mild reaction conditions and simple operation.The better technology conditions for the preparation of N-propylidene-benzylamine from benzylamine are as follows: reaction temperature is 0 ; reaction time is 2 hours; the ratio of benzylamine to propionaldehyde is l:l(molar ratio); potassium hydroxide (pellets) is added to remove the water formed in the reaction; the reaction is best carried out by adding the propionaldehyde to the benzylamine; the dryer is no aqueous calcium chloride. Its yield is 90.3%.N-benzyl-N-(l-propenyl)-acetamide is prepared better with the yield of 83.7% and the purity of 98.1% as follows: reaction temperature is room temperature; reaction time is 2 hours; the ratio of N-propylidenebenzylamine to acetic anhydride and triethylamine is 1:1:1 (molar ratio).After many single factors experiments and quadrature experiment, the better reaction condition in which 2-chloro-5-methylpyridine is synthesized as follows: the solvent is toluene: the ratio of N-benzyl-N-(l-propenyl)-acetamide to N.N-Dimethyl Formamide and triphosgene is 1:1.4:0.7(molar ratio); reaction temperature is 120 ; reaction time is 3 hours: the reaction is best carried out by adding the N-benzyl-N-(l-propenyl)-acetamide and N.N-Dimethyl Formamide simultaneity to reactor: Its yield is 84.8% with the purity of 98.1%. Comparing to other routes, the route have some merits as following: the reaction is comparatively simple, short steps, mild reaction conditions. Triphosgene instead of phosphorus oxychloride, phosgene and so on.Nicotinic acid ethyl ester are applied widely in synthesis of medicines andinsecticides. The relation between their chemical structure and biological activity is depended on affect of substituents in different postion of pyridine ring. Three nicotinic acid ethyl ester(I , II, III) are synthesised with the yield of 41.0-50.5% from 2-chloro-5-methylpyridine via oxidition, nitration, deoxidition, chlorination, acylation, esterification.In the preparation of 2-Chloropyridine-5-methylpyridine-N-Oxide the reaction is best carried out by adding to oil of vitriol as catalyzer. It makes the operation simply and reaction velocity accelerated . The ratio of 2-Chloropyridine-5-methylpyridine, H2SO4(98%), glacial acetic acid and hydrogen penoxide is 1: 0.3: 1.6: 1.5 (molar ratio). Its yield is 88.1%.In the preparation of 2-Chloropyridine-5-methyl-4-nitropyridine-N-oxide, a suitable condition of subsituting 65% nitric acid for fuming nitric acid and deoxidition was studied. The better reaction condition in which 2-chloro-5-methyl-4-nitro-pyridine-N-oxide is synthesized as follows: 65% nitric acid instead of fuming nitric acid; reaction temperature is 90 ; reaction time is 4 hours. It yield is 88.0%.In the preparation of 2-Chloropyridine-5-methyl-4-nitropyridine and 2.4-dichchro-5-methylpyridine. the better reaction condition in which 2-chloro-5-methyl-4-nitropyridine is synthesized as follows: reaction temperature is 60 ; reaction time is 2 hours. Its yield is 91.3%. Another better reaction conditions in which 2,4-dichchro-5-methylpyridine is synthesized as follows: reaction temperature is 78 : reaction time is 3 hours. It yield is 82.7%.In the preparation of nicotinic acid ethyl ester, the reaction is acylated and then esterificated. This step can improve yields and purificate sample.Among them synthetic methods of compounds 2-Chloropyndine-5-methylpyridine. 2,4-dichchro-5-methylpyridine aren t reported in the literature and 6-chloro-4-nitro nicotinic acid , 6-chloro-4-nitro nicotinic acid ethyl ester are new compounds. The structure of related compounds was identified by IR or MS.
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