Benzimidazolone Pigments and Related Structures

7 октября, 2015

Pokraskin

Hans-Joachim Metz and Frank Morgenroth

Benzimidazolone pigments are azo colorants that derive their name from the benzimidazolone group which is introduced as part of the coupling component. Apart from one exception1 there are two coupling components of commercial importance: 5-acetoacetylaminobenzimidazolone (1) and 5-(2′-hydroxy-3′-

naphthoylamino)-benzimidazolone [Naphtolon™] (2) (see Figure 10.1).

Figure 10.1 The two commercially relevant coupling components for benzimidazolone pigments.

While the acetoacetyl derivative 1 provides greenish yellow to orange products, the naphthoylamino compound 2 affords colorants having medium red to carmine, maroon, bordeaux or brown shades. Figure 10.2 summarizes the Colour Index data [1], shades and structural formulae of commercial available benzimid — azolone pigments.

1) P. O. 64 is prepared by coupling diazotized 5-amino-6-methylbenzimidazolone onto barbituric acid.

Figure 10.2b Colour Index data, shades and structural formulae of commercially available benzimidazolone pigments (red and brown).

C. I.	C. I.	1st known	Shade:	R1 R2 R*3	CAS index name/chemical
name:	const.	product:			formula:
	no./CAS
	no.:
P. R	12513/	Permanent™	bluish	-COOCH3 — H — H	Benzoic acid, 2-[[3-[[(2,3-
175	6985-92-	Red HFT	red		dihydro-2-oxo-1H-
	8				benzimidazol-5-yl)amino]- carbonyl]-2-hydroxy-1- naphthalenyl]azo]-, methyl ester/ C26H,9N5O5
P. R.	12515/	Permanent™	bluish	-OCH3 — H — CONHC6H5	2-Naphthalenecarboxamide,
176	12225-	Carmine	red		N-(2,3-dihydro-2-oxo-1H-
	06-8	HF3C			benzimidazol-5-yl)-3-hy- droxy-4-[[2-methoxy-5-[(phe- nylamino)carbonyl]pheny- l]azo]-/C32H24N6O5
P. R.	12516/	Permanent™	bluish	-OCH3 — SO2NHCH3 — CH3	2-Naphthalenecarboxamide,
185	51920-	Carmine	red		N-(2,3-dihydro-2-oxo-1H-
	12-8	HF4C			benzimidazol-5-yl)-3-hy- droxy-4-[[2-methoxy-5-meth- yl-4-[(methylamino)sulfo- nyl]phenyl]azo]-/ C27H24N6O6S
P. R.	12514/	PV Red	bright	-COOC4H9(n) — H — H	Benzoic acid, 2-[[3-[[(2,3-
208	31778-	HF2B	red		dihydro-2-oxo-1H-
	10-6				benzimidazol-5-yl)amino]- carbonyl]-2-hydroxy-1- naphthalenyl]azo]-, butyl ester//C29H25N5O5

C. I.	C. I.	1st known	Shade: R*1	R2 R3	CAS index name/chemical
name:	const.	product:			formula:
	no./CAS
	no.:
P. V	12517/	PV Fast Bor-	reddish — OCH3	-so2nhch3 — och3	2-Naphthalenecarboxamide,
32	12225-	deaux HF3R	violet		N-(2,3-dihydro-2-oxo-1H-
	08-0				benzimidazol-5-yl)-4-[[2,5- dimethoxy-4-[(methylamino) sulfonyl]phenyl]azo]-3-hy- droxy-//C27H24N6O7S
P. Br.	12510/	Hostaperm™	reddish — Cl	-H — Cl	2-Naphthalenecarboxamide,
25	6992-	Brown HFR	brown		4-[(2,5-dichlorophenyl)azo]-
	11-6				N-(2,3-dihydro-2-oxo-1H- benzimidazol-5-yl)-3-hy- droxy-/C24H15Cll2N5O3