Patent ID: 7557216

Claim:
A process for producing a 5-chloro-2,4-dihydroxypyridine represented by formula (1): characterized in that the process comprises reacting a 5-chloro-1,3-dioxin-4-one derivative (2) represented by formula (2): (wherein R 1 and R 2 , which are identical to or different from each other, each represent a C1 to C6 linear-chain or branched-chain alkyl group, or R 1 and R 2 may be linked to form a C3 to C6 cycloalkane with adjacent carbon atoms) with a ketene acetal derivative (3) represented by formula (3): (wherein R 3 and R 4 , which are identical to or different from each other, each represent a C1 to C6 linear-chain or branched-chain alkyl group, or a silyl group having a C1 to C6 linear-chain or branched-chain alkyl group), to thereby form a pyrone derivative (4) represented by formula (4): (wherein R 3 and R 4 have the same meanings as defined above); treating the pyrone derivative (4) with an acid; and subsequently, reacting the product with ammonia.