4-[(5-carbamoyl-o-tolyl)azo]-3-hydroxynaphth-2-anilide

The IUPAC name of Pigment Red 268 is (4Z)-4-[(5-carbamoyl-2-methylphenyl)hydrazinylidene]-3-oxo-N-phenylnaphthalene-2-carboxamide. With the CAS registry number 16403-84-2, it is also named as 2-Naphthalenecarboxamide, 4-(2-(5-(aminocarbonyl)-2-methylphenyl)diazenyl)-3-hydroxy-N-phenyl-. In addition, this chemical is bright red powder which is used to color ink, fabric, paint, plastic and so on.

The other characteristics of this product can be summarized as: (1)ACD/LogP: 5.13; (2)# of Rule of 5 Violations: 1; (3)ACD/LogD (pH 5.5): 5.13; (4)ACD/LogD (pH 7.4): 5.13; (5)ACD/BCF (pH 5.5): 4645.95; (6)ACD/BCF (pH 7.4): 4645.26; (7)ACD/KOC (pH 5.5): 14671.72; (8)ACD/KOC (pH 7.4): 14669.54; (9)#H bond acceptors: 7; (10)#H bond donors: 4; (11)#Freely Rotating Bonds: 6; (12)Index of Refraction: 1.673; (13)Molar Refractivity: 121.01 cm³; (14)Molar Volume: 322.5 cm³; (15)Polarizability: 47.97×10^-24 cm³; (16)Surface Tension: 54.5 dyne/cm; (17)Enthalpy of Vaporization: 95.18 kJ/mol; (18)Vapour Pressure: 6.18E-16 mmHg at 25°C; (19)Rotatable Bond Count: 5; (20)Tautomer Count: 131; (21)Exact Mass: 424.153541; (22)MonoIsotopic Mass: 424.153541; (23)Topological Polar Surface Area: 114; (24)Heavy Atom Count: 32; (25)Complexity: 799.

Preparation of Pigment Red 268: 150 copies of 3-amino-4-methylbenzamide suspends in 1500 copies of water, and then using 265 copies of concentrated hydrochloric acid and 72 copies of sodium nitrite to conventional diazotization. Adding the mixture of 298 copies of N-(2-hydroxy-3-naphthoyl) aniline, 1500 copies of  hot water and 127 copies of sodium hydroxide to diazonium solution under stirring. Stirring a little and then heating to 70 ~ 95 °C. Adding 161 copies of acetic acid and 65 copies of sodium acetate. After filtration and drying, we can get the product.

People can use the following data to convert to the molecule structure.
1. SMILES: NC(=O)c4cc(N=Nc2c3ccccc3cc(C(=O)Nc1ccccc1)c2O)c(C)cc4;
2. InChI: InChI=1/C25H20N4O3/c1-15-11-12-17(24(26)31)14-21(15)28-29-22-19-10-6-5-7-16(19)13-20(23(22)30)25(32)27-18-8-3-2-4-9-18/h2-14,30H,1H3,(H2,26,31)(H,27,32).