| abstract |
1,244,767. Methin, azamethin and azo dyes. INTERNATIONAL BUSINESS MACHINES CORP. 26 Aug., 1968 [18 Sept., 1967], No. 759/71 Divided out of 1,244,764. Heading C4P. [Also in Division C2] Methine, azamethine and azo dyes are of formulµ- (in which R is halogen or 1-4 C alkyl or alkoxy; R 2 and R 3 are both R 5 -(CH = CH) n -CH = N-, R 5 -(CH=CH) m - or R 5 -N=NR 5 is C 6 H 5 - or p-(CH 3 ) 2 N-C 6 H 4 -; n is 0-3, m is 1-4). The methine and azamethine dyes are prepared by condensing an aldehyde with a compound in which R 2 and R 3 are NH 2 or CH 3 (see Division C2). The azo dyes are prepared by reacting N,N-dimethylaniline with the diazotization product of a compound in which R 2 and R 3 are NH 2 . |