| 摘要 |
PURPOSE:To obtain a new compound having excellent coloring performances at a low temperature when used as a coloring compound for a heat-sensitive recording material. CONSTITUTION:A crystalline propanol bonded substance of a fluoran compound of formula I. The compound is obtained by precipitation as crystal from a propanol solution containing the compound of formula I. Generally, the substance is obtained by dissolving the compound of formula I in propanol at room temperature to the boiling point of a solvent and precipitating while stirring or by allowing to stand. The compound of formula I is preferably obtained by condensing a benzoic acid derivative of formula II with a diphenylamine derivative of formula III (R is lower alkyl) through dehydration in the presence of a dehydrating condensation agent such as concentrated sulfuric acid at 0-50 deg.C, treating the reaction mixture with an alkali at 0-100 deg.C and adjusting to pH9-12. |
