Method for preparing 2-hydroxy-6-ureidocarbonyl naphthalene derivative

A method for manufacturing a 2-hydroxy-6-ureidocarbonyl naphthalene derivative, which comprises the step of reacting a 2-hydroxy-6-aminocarbonyl naphthalene derivative represented by formula [1]:

• wherein X is hydrogen atom, cyano group or a group represented by formula [2], [3] or [4] below:
• —CONH—X1 [2]
• wherein X1 is selected from the group consisting of an optionally branched and optionally substituted C1–20 aliphatic hydrocarbon group which may have unsaturated bond(s), an optionally substituted aromatic group and an optionally substituted heterocyclic group having conjugated double bonds;
• —CO—O—X2 [3]
• wherein X2 is an optionally branched C1–6 aliphatic hydrocarbon group which may have unsaturated bond(s);
• wherein A is selected from the group consisting of an optionally substituted aromatic group and an optionally substituted heterocyclic group having conjugated double bonds, and
• Z is selected from the group consisting of —O—, —S— and —NH—;
• Q is selected from the group consisting of optionally branched C1–6 alkyl and alkoxy groups, halogen atom, nitro group and nitroso group;
• n is an integer of 0–3;
• and
• R1 is selected from the group consisting of hydrogen atom, C1–6 alkyl, C2–6 acyl and phenylalkyl groups,
• with a isocyanate represented by formula [5]:
• OCN—Y [5]
• wherein Y is selected from the group consisting of an optionally substituted aromatic group and an optionally substituted heterocyclic group having conjugated double bonds,
• in an organic solvent at a temperature of 90–200° C. to give the 2-hydroxy-6-ureidocarbonyl naphthalene derivative represented by formula [6]:
• wherein X, Q, n, R1 and Y are the same as defined above.