PURPOSE: To obtain the subject new compound useful as an intermediate capable of producing a 2,4-dihydroxy-5-halogenopyridine derivative, an inhibitor against enzymic bisdegradution of anti-malignant tumor agent 5-fluorouracil, under a mild condition in a short process.
CONSTITUTION: A 3-substituted-5-halogenopyridine derivative of formula I (R and R' are lower alkyl or H; (x) is halogen; Y is CN or CONH2) such as 5- chloro-3-cyano-4-methoxy-2-oxo-1,2-dihydropyridine. A compound of formula Ia among the compounds is obtained by reacting a 3-cyanopyridine derivative of formula III with a halogenating agent in a proper solvent and a compound of formula Ib is obtained by heating the compound of formula Ia with sulfuric acid under reflux. The compound of formula I is reacted with a mineral acid such as hydrochloric acid, hydrobromic acid or sulfuric acid in a proper solvent to advantageously produce a compound of formula II useful as the enzyme inhibitor.
ONO TOMOYASU
OGAWA KAZUO
SHIRASAKA TETSUHIKO
