| 摘要 |
PROBLEM TO BE SOLVED: To provide a new electron-acceptable compound that loses its electron acceptance competence with thermal energy and is useful in the thermally sensitive recording materials. SOLUTION: This is an electron-accepting compound that irreversibly loses its electron acceptance competence with thermal energy. This compound is preferably represented by formula II (X<1> to X<3> are each H, an alkyl, an alkenyl or the like; L is a divalent linkage group) having at least one of the functional group of formula I [p is 1 or 2; R<1> is H, an alkyl, an alkenyl or the like; R<2> is an alkyl, an alkenyl, an aralkyl or the like; Y is -O-, -S-, -R<8> - (R<3> is H, an aralkyl or the like)], typically the compound of formula III. This compound is prepared, for example, by dripping a solution of di-t-butyl bicarbonate in tetrahydrofuran into anthranilic acid, sodium hydroxide and distilled water, stirring the reaction mixture at room temperature and adding a small amount of citric acid under cooling with ice. |
