To obtain the subject compound useful as an intermediate compound of a compound for a pressure sensitive and thermally sensitive recording material pigment by condensing a 1-alkoxy-1,1'-bis-(4-dialkylaminophenol)-methane with m-diaminobenzoic acid or its derivative in a mineral acid solution.
This method for producing a 2-[4,4'-bis(dialkylamino)- benzohydryl]-5-dialkylaminobenzoic acid, is constituted by slowly dripping an aqueous solution obtained by adding 0.5-3.0 equivalent mineral acid such as hydrochloric acid and boric acid to an aquebous 1-alkoxy-1,1'-bis(4- dialkylaminophenol)-methane, into an aqueous solution or a slurry of m- diaminobenzoic acid or its derivative under an inert atmosphere, condensing by maintaining the system at a room temperature to 100°C, and then isolating the objective compound as a leuco compound expressed by the formula (R1 to R4 are each a 1-8C alkyl; R5, R6 are each H or a 1-8C alkyl) by a raising the pH of the system to 3-6 by using an alkali metal hydroxide, a carbonic acid salt, etc., in the system.
| WO/1998/007685 | PREPARATION OF CYCLOHEXENE CARBOXYLATE DERIVATIVES |
| WO/1996/037458 | PROCESS FOR THE PREPARATION OF A HALOSUBSTITUTED AROMATIC ACID |
YAMAZAKI TAKESHI
MIZUKAWA KUNIO
FUKUOKA NAOHIKO
