| 摘要 |
<p>Disclosed are: a process for producing a 1-substituted-2-pyridone-3-carboxylic acid derivative which is an important intermediate for the production of a 2-pyridone-3-carbamoyl derivative that has a cannabinoid receptor agonist activity in a simple manner; and a process for producing the 2-pyridone-3-carbamoyl derivative in a simple manner. Specifically disclosed is a process for producing a compound represented by the general formula (II), which comprises: a step A for hydrolyzing a compound represented by the general formula (I); and a step (B) for adding an alcohol to the hydrolysate of the compound represented by the general formula (I) produced in the step A to produce a crystal of the compound represented by the general formula (II). (I) wherein R1 represents an alkyl which may be substituted by a non-reactive substituent, or the like; R2 and R3 independently represent an alkyl or the like, or R2 and R3, together with a carbon atom adjacent to R2 and R3, may form a cycloalkene; R4 represents a hydrogen atom or the like; and R5 represents an alkyl. (II) wherein R1, R2, R3 and R4 are as defined above.</p> |
