| 摘要 |
<p>The present invention relates to the synthesis of a hydrazone beta -keto ester by the reaction of an alkyl diazo ester with a hydrazone aldehyde in the presence of a Lewis acid. In a preferred embodiment, the hydrazone beta -keto ester is then converted into a pyridazinone compound by the reaction with an alkyl acid chloride in the presence of a base, followed by acidification. The present invention also relates to a continuous process for the production of a hydrazone aldehyde comprising contacting a hydrazine and glyoxal, wherein the hydrazine and the glyoxal are added simultaneously to a reactor at a controlled rate.</p> |
