PURPOSE: To obtain a 2-amino-4-pyridylmethyl-6-hydroxybenzothiazole derivative useful as an agent for preventing and treating diseases for which a lipoxygenase- inhibiting action is effective, by a new method using an amino- pyridylhydroxymethyl-hydroxybenzothazole derivative as a raw material.
CONSTITUTION: A 2-amino-4-pyridylhydroxymethyl-6-hydroxybenzothiazole derivative of formula I (R1 is H, methyl, methoxy; R2, R3 are H, lower alkyl) [e.g. 4-methoxy(3-pyridyl)methyl-6-hydroxy-5,7-dimethyl-2-methylaminobenzothiazole] is reduced with zinc in acetic acid to obtain the objective compound of formula II. In the reaction, the acetic acid is preferably used in an amount of 1-10 volumes per pt.wt. of the compound of formula I, and the zinc is used in an amount of 2-30 equivalents based on the compound of formula I under refluxing the solvent. The reaction time is usually 6 hrs to 2 days.
MINAMI NORIO
YAMAGISHI YOJI
FURUKAWA TAKESHI
NISHIMURA HIROSHI
EISAI KAGAKU KK