Organic compounds -- part of the class 532-570 series – Organic compounds – Azo
Patent
1997-11-04
1999-10-12
Higel, Floyd D.
Organic compounds -- part of the class 532-570 series
Organic compounds
Azo
534825, 855296, 548365, 5483054, 558394, C07C24508, C07C25517, C07D40312, C07D23526
Patent
active
059657170
ABSTRACT:
Nonmutagenic, highly twisted derivatives of benzidine of the following formula ##STR1## useful as intermediates for the preparation of various organic pigments were obtained. The benzidine derivatives are significantly rotated about the biphenyl linkage due to bulky substituents at the R.sub.2 and/or R.sub.4 positions. Bisazomethine, disaoacetoacetanilide, disazopyrazolone, disazobenzimidazolone and disazonaphthol pigments prepared from these highly twisted benzidines exhibit hypsochromic spectral shifts relative to pigments prepared from other benzidine compounds with less twist about the biphenyl linkage, for instance, other benzidine compounds in which all four R.sub.2 and R.sub.4 represent H. Greenish-yellow, yellow, orange, red and brown pigments obtained from the twisted benzidines are nonmutagenic in the standard Ames test and Prival modification.
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Freeman Harold S.
Hinks David
Sokolowska-Gajda Jolanta
Higel Floyd D.
Keating Dominic
North Carolina State University
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