| 摘要 |
A process for the preparation of a pyrazine derivative of the formula <IMAGE> I wherein R1 represents hydroxy, C1-C6 alkoxy, or a group of the formula NR2R3 in which R2 and R3 are independently a hydrogen atom or C1-C6 alkyl or, together with the nitrogen atom to which they are linked, form a saturated ring having five or six atoms which may contain one or more additional heteroatoms; which process comprises reacting a compound of the formula: <IMAGE> II wherein R represents a hydrogen atom, C1-C6 alkyl, or C1-C6 alkoxy, Y represents a hydrogen atom or a sodium, lithium, or potassium ion, and A is a nitrile group or a substituent of the formula COR1 where R1 is as defined above either with pyruvic aldehyde oxime of the formula: <IMAGE> III or with a pyruvic aldehyde oxime acetal derivative of the formula: <IMAGE> IV wherein R4 and R5 are independently a hydrogen atom or C1-C6 alkyl or may be linked together so that the compound of formula IV is a cyclic acetal; and, when A is a nitrile group, hydrolyzing the reaction product. |
