| 摘要 |
NEW MATERIAL:A compound expressed by formula I (R1 and R2 represent H, alkyl, 5-6C cycloalkyl or benzyl; R3 and R4 represent H or alkyl; R5 represents 1-8C alkyl or benzyl optionally substituted with alkyl; R6-R8 represent H or methyl; provided that not only R1 and R2 but also R3 and R4 may link with each other and form, together with the N atom to which they bond, pyrrolidine, piperidine or morpholine). EXAMPLE:A compound expressed by formula II. USE:A coloring component of a coloring recording substance, which is normally colorless - light yellow powder and forms a green - blue coloring matter by action of an acidic substance and absorbs electromagnetic waves ranging from a visible region to a near infrared region. PREPARATION:For example, a compound expressed by formula III is dissolved in sulfuric acid and subjected to diazotization reaction at a temperature as low as <=0 deg.C. Then a catalyst such as copper powder, etc., is added and the cyclization reaction is carried out for example at 80 deg.C for 24hr while stirring. |
