5- -benzimidazolone

BenZimidaZolones. This class of pigments derives its name from 5-aminobenzimidazolone/Pj5 -2J-< 7 which upon reaction with diketene or 2-hydtoxy-3-naphthoyl chloride leads to compounds which can be coupled with a variety of diazotized amines. 

Infrared spectral data have been advanced to support the oxo formulation for 96 (R —propyl). Structure 96 (R= phenyl) has also been proposed on the basis of the fact that benzoin does not condense with urea, and this conclusion is probably correct, although the argument is not convincing. The oxo forms of benzimidazolone, 97 106,10- related pyrazinoimidazolone 98 have been shown... 

A series of benzimidazole and benzimidazolone derivatives from the Janssen laboratories has provided an unusually large number of biologically active compounds, particularly in the area of the central nervous system. Reaction of imidazolone itself with isopropenyl acetate leads to the singly protected imidazolone derivative 51. Alkylation of this with 3-chloro-l-bromopropane affords the functionalized derivative Use of this... 

A somewhat more complex scheme is required for the preparation of benzimidazolones in which one of the nitrogen atoms is substituted by a 4-pi peridyl group. The sequence starts with aromatic nucleophilic substitution on dichlorobenzene by protected amino-piperidine derivative to give Reduction of the... 

Chemical Name 1-[3-[4-(Dlphenvlmethyl)-1-piperazlnyl] propyl] -2-benzimidazolone Common Name Oxatimide Structural Formula / ... 

Ethyl acetoacetate affords a mixture of 19c and the benzimidazolone 20 under these conditions 272-273 however, only the benzodiazepinonc 19c is formed in the reaction of benzene-1,2-diamine with diketene (see Houben-Weyl, Vol. 7/4, p 236).274... 

In addition to the imidazole-based compounds detailed earlier, more recently the Schering-Plough group reported on several new series of H3 antagonists including oximes (47) [121], benzimidazoles (48) [122], benzimidazolones (49) [123], and indoles (50) [124]. All of the compounds shown have K] of less than 10 nM in guinea-pig brain. 

Figure 9.3 Intermolecular association in the crystal structure of a benzimidazolone azo pigment...

Benzil, 3 594 14 594 Benzilonium bromide, 4 359t Benzimidazoles, microwave-assisted synthesis of, 16 574-575 Benzimidazolethiols, 25 197 Benzimidazolone dioxazine, 19 446 Benzimidazolone pigments, 19 432 433 Benzimidazolone Violet, pigment for plastics, 7 367t Benzine, 3 597... 

To obtain the necessary fastness properties, high-quality pigments are generally used for security printing. The range of suitable products covers disazo, disazo condensation, benzimidazolone, naphthol AS, isoindolin, perinone, anthanthrone, dioxazine and quinacridone pigments. 

The prints tolerate white spirit, dibutyl phthalate, butter, soap, alkali, and acid. Moreover, they are also stable to clear lacquer coating their fastness to sterilization, on the other hand, exceeds that of P.R.57 1, but is not perfect. Where sterilization fastness is required, P.R.146 is superseded by P.R.185, a benzimidazolone pigment, which is its coloristically closest neighbor. 

A few years ago the pigment was withdrawn from the market. P.R.212 was rarely sold outside Japan. It produces considerably bluish shades of red, which might be considered pink. Compared to the similarly colored quinacridone pigment P.R.122, P.R.212 is duller, weaker, and less fast. 1/3 SD letterpress proof prints, for instance, equal step 2-3 on the Blue Scale for lightfastness while prints containing P.R.122 equal step 6-7. P.R.212 is also less lightfast than the somewhat more bluish and duller benzimidazolone pigment P.V.32, a coloristically related maroon the difference is 2 to 3 steps on the Blue Scale. 

Benzimidazolone pigments [1, 2] derive their name from the 5-aminocarbonyl benzimidazolone group (22), which is common to all pigments within this group ... 

Although, strictly speaking, it would be more precise to refer to such compounds as benzimidazolone azo pigments, the convention of listing them as benzimidazolone pigments will be followed. 

---