To obtain a chromone derivative having an action for inhibiting the neurocyte necrosis and useful for treating senile dementia of Alzheimer's disease, Down's syndrome, vascular dementia, Parkinson's disease, etc.
A compound of the formula [R is a carboxy-(1-6C)alkyl, a carboxy-(2-6C)alkenyl or the like], for example, {4-[(7-isopropoxy-5,6- dimethoxy-4-oxo-4H-chromen-2-yl)thio]phenoxy}methyl pivalate. The compound of the formula is obtained by converting the phenolic hydroxyl group of 2-[(4- hydroxyphenyl)thio]-7-isopropoxy-5,6-dimethoxy-4H-chromen-4-one into an ether, ester, carbonate ester, carbamate ester, thiocarbamic acid O-ester, sulfonate ester or phosphate ester. The purification of the product is carried out by a column chromatography method using silica gel as a carrier or by a recrystallization method using methanol, etc.
TANAKA MASAHIDE
YANAGISAWA ERIKA
YAMAGUCHI TAKUJI
