2,3-DIHYDRO-1,4-BENZOXAZINE COMPOUND

摘要

PROBLEM TO BE SOLVED: To provide a new 2,3-dihydro-1,4-benzoxazine compound having type-4 phosphodiesterase inhibiting action and useful as antiasthmatic agent, bronchoconstriction suppressing agent, etc. SOLUTION: The objective compound is expressed by formula I [R3 and R2 are each H, a (substituted)1-6C alkyl or the like; R3 to R5 are each a halogen or the like; R6 is cyano or the like; R7a is H or the like; R7b is cyano or the like; R8 is H, a (substituted)1-6C alkyl or the like; X is O or the like], e.g. the compound of formula II. The compound of formula I can be produced e.g. by reacting 2H-1,4-benzoxazin-3(4H)-one with lithium aluminum hydride, separately producing a tosyl compound by the reaction of 3,4-dimethoxyphenethyl alcohol with p-toluenesulfonyl chloride and triethylamine and reacting the product of the former reaction with the tosyl compound in the presence of potassium carbonate.