| 摘要 |
NEW MATERIAL:A compound of formula I (wherein R<1> is H, an aldehyde, a cyano or a lower alkoxycarbonyl; R<2> is O, S, =NH or a group of formula II; R is a lower alkyl or a halogen atom; and n is 0-5). EXAMPLE:A compound of formula III. USE:An azulene compound useful as a colorant of an optical recording medium. PREPARATION:A compound of formula IV and squaric acid of formula V are heated under reflex in an organic solvent mixture such as toluene/butanol, while removing the formed water from the reaction system. |
