.1 - Hydroxypyridine Synthesis Of Ketones

1-Hydroxy-4-methyl-6(2,4,4-trimethylpentyl)2-pyridon monoethanolamine salt(Octopirox) is a kind of powerful anti-dandruff agent with advantages on removing dandruff over other ones.It has good cooperation with other components of shampoo.And it is safe to people with no stimulation,no toxic.So,Octopirox has great application value. Numerous methods were reported for the synthesis of these structures over the last few decades,although these methods were valuable for the preparation of 1-hydroxy-4-methyl-6(2,4,4-trimethylpentyl)2-pyridon monoeth- anolamine salt,many were associated with drawbacks,such as costly, high toxicity,drastic action,hard loan.Thus an important practical for the preparation of these compounds is essential.The preparation of methyl 3-methyl-2-butenoate.First method using isobutyraldehyde and hydrocyanic acid as raw materials, 2 - hydroxy -3-- methyl butyronitrile can be obtained. The synthesis of methyl 2-hydroxy-3-methylbutanoate with 2 - hydroxy -3-- methyl butyronitrile and methanol as reactants and sulfuric acid as catalyst has been studied. The synthesis of methyl 2-hydroxy-3-methylbutanoate elimination of water, acid to obtain 3-methyl-2-butenoic acid, but this step tried a lot of conditions, did not succeed, we need to further exploration. Second method using acetone as raw materials, isopropyliden eacetone can be obtained.3-methyl-2-butenoic acid is obtained from the oxidation of isopropyliden eacetone, The synthesis of methyl 3-methyl-2-butenoate with 3-methyl-2-butenoic acid and methanol as reactants and phosphorus oxychloride as catalyst has been studied. The effects of reaction conditions on the yield, the optimum process conditions.We have improved the previous synthetic methods, reduced the reaction costs, simplified the operation process for 1-hydroxy-4-methyl-6(2,4,4-trimethylpentyl)2-pyridon monoethanolamine salt.4-methyl-6-(2,4,4-trimethylpentyl)-2-pyrone is prepared with 3,5,5-trimethylhexanoyl chlor- ide and methyl 3-methyl-2-butenoate by acyl chlorination,acylation and cyclization reaction. The preparation of 1-hydroxy-4-methyl-6-(2,4,4-tri-methylpentyl)-2-pyrid-one by reaction of 4-methyl-6-(2,4,4-trimethylpentyl)-2-pyrone with hydroxylammonium chloride. 1-hydroxy-4-m ethyl-6-(2,4,4-trimethylpentyl)-2-pyridone react with monoethanolamine form 1-hydroxy-4-met hyl-6(2,4,4-trimethylpentyl)2-pyridon monoethanolamine salt.we discussed the effects of reaction time, reaction temperature, catalyst, and ratio of substrate in each step ,and the suitable conditions for the process have been obtained. The intermediate and final products were characterized by 1HNMR, IR .