| 摘要 |
PROBLEM TO BE SOLVED: To obtain a leuco color of which the color-developing matter has absorpion in a specified wavelength range by conducting the step of reacting a specific indole compd. with acetyl chloride in acetic anhydrive and the step of reacting the reaction product of the former step with a benzoic acid deriv. successively in one pot. SOLUTION: The first step wherein an indole compd. represented by formula I (wherein R<1> is an alkyl, cycloalkyl, or aralkyl; and R<2> is methyl or phenyl) is reacted with acetyl chloride in acetic anhydride and the second step wherein the reaction product of the former step is reacted with a benzoic acid deriv. represented by formula II (wherein R<5> and R<6> are each an alkyl, cycloalkyl, aralkyl, or aryl provided they may combine with each other to form an N-contg. heterocycle; and R<7> is H, an alkyl, alkoxy, or cycloalkoxy) are conducted successively in one pot to give a phthalide compd. represented by formula III (wherein R<1> , R<2> , R<5> , R<6> , and R<7> are each the same as in formula I or II). This color- developing matter has absorption in 570-780nm and is useful as an electron- donating leuco color. |
