IUPAC Name: (2Z)-6-Chloro-2-(6-chloro-4-methyl-3-oxo-1-benzothiophen-2-ylidene)-4-methyl-1-benzothiophen-3-one
Synonyms of Pigment Red 181 (CAS NO.2379-74-0): Vat Red 1 ; Vat Pink R ; 6-Chloro-2-(6-chloro-4-methyl-3-oxobenzo[b]thien-2(3H)-ylidene)-4-methylbenzo[b]thiophene-3(2H)-one
CAS NO: 2379-74-0
Molecular Formula: C₁₈H₁₀Cl₂O₂S₂
Molecular Weight: 393.31
Molecular Structure:
EINECS: 219-163-6
H bond acceptors: 2
H bond donors: 0
Freely Rotating Bonds: 0
Polar Surface Area: 84.74 Å²
Index of Refraction: 1.751
Molar Refractivity: 101.29 cm³
Molar Volume: 248.3 cm³
Surface Tension: 71.1 dyne/cm
Density: 1.583 g/cm³
Flash Point: 273.8 °C
Enthalpy of Vaporization: 80.41 kJ/mol
Boiling Point: 529.1 °C at 760 mmHg
Vapour Pressure: 2.78E-11 mmHg at 25°C 
Colour Index: 73360 
Product Categories of Pigment Red 181 (CAS NO.2379-74-0): Organics 
SMILES: Clc1cc(c2C(=O)C(\Sc2c1)=C4/Sc3cc(Cl)cc(c3C4=O)C)C
InChI: InChI=1/C18H10Cl2O2S2/c1-7-3-9(19)5-11-13(7)15(21)17(23-11)18-16(22)14-8(2)4-10(20)6-12(14)24-18/h3-6H,1-2H3/b18-17+
InChIKey: NDDLLTAIKYHPOD-ISLYRVAYBI
Std. InChI: InChI=1S/C18H10Cl2O2S2/c1-7-3-9(19)5-11-13(7)15(21)17(23-11)18-16(22)14-8(2)4-10(20)6-12(14)24-18/h3-6H,1-2H3/b18-17+
Std. InChIKey: NDDLLTAIKYHPOD-ISLYRVAYSA-N

Safety Information about Pigment Red 181 (CAS NO.2379-74-0):
Safety Statements: 23-24/25 
S23: Do not breathe vapour. 
S24/25: Avoid contact with skin and eyes.
RTECS: DL9825500