| 摘要 |
PROBLEM TO BE SOLVED: To obtain a new salicylic acid derivative capable of providing a thermal recording material excellent in storage stability of uncolored part and colored image by using the derivative as an electron-accepting compound. SOLUTION: This compound is shown by formula I (X1 and X2 are each H, a halogen, a 1-8C alkyl, a 5-8C cycloalkyl, a 1-8C alkoxy, a 7-10C aralkyl or a 6-10C aryl; Y1 and Y2 are each or S; R is a 3-24C alkyl, a 5-24C cycloalkyl, a 2-24C alkenyl, a 7-24C aralkyl or a 6-24C aryl; (m) is 1-4; M is H or a m- valent metal element) and its metal salt such as 3-(n-butyloxycarbonyloxy) salicylic acid. The compound of formula I is obtained by reacting a compound of formula II with a compound of formula III (Z is a halogen) in the presence of a base and optionally water or an organic solvent. |
