Dating back to the 15th century as the azure-blue chromophore, Azulene (CAS NO.275-51-4) obtained by steam distillation of German chamomile.Its structure and first synthesis were reported by Lavoslav Ru?i?ka, followed in 1937 by Placidus Plattner.The chromophore was discovered in yarrow and wormwood and named in 1863 by Septimus Piesse.

Reported in EPA TSCA Inventory.

Azulene is an organic compound with the formula C₁₀H₈, and its systematic name is the same with the product name. With the CAS registry number 275-51-4, it is also named as Cyclopentacycloheptene. It belongs to the product categories of Aromatic Hydrocarbons (substituted) & Derivatives; Tropolones & Azulenes; Azulenes. Its EINECS number is 205-993-6. In addition, the molecular weight is 128.17. Its classification codes are: (1)Analgesics; (2)Analgesics, Non-Narcotic; (3)Anti-Inflammatory Agents; (4)Anti-inflammatory agents, non-steroidal; (5)Antirheumatic Agents; (6)Peripheral Nervous System Agents; (7)Sensory System Agents. This chemical should be sealed and stored in a cool and dry place. Moreover, it should be protected from light. In organometallic chemistry, azulene serves as a ligand for low-valent metal centers. It is reported to be anti-inflammatory principle of Matricaria. When heated, it can rearrange into naphthalene. 

Physical properties of Azulene are: (1)ACD/LogP: 3.361; (2)# of Rule of 5 Violations: 0; (3)ACD/LogD (pH 5.5): 3.36; (4)ACD/LogD (pH 7.4): 3.36; (5)ACD/BCF (pH 5.5): 211.02; (6)ACD/BCF (pH 7.4): 211.02; (7)ACD/KOC (pH 5.5): 1604.58; (8)ACD/KOC (pH 7.4): 1604.58; (9)#H bond acceptors: 0; (10)#H bond donors: 0; (11)#Freely Rotating Bonds: 0; (12)Index of Refraction: 1.632; (13)Molar Refractivity: 44.095 cm³; (14)Molar Volume: 123.549 cm³; (15)Polarizability: 17.481×10^-24cm³; (16)Surface Tension: 40.2 dyne/cm; (17)Density: 1.037 g/cm³; (18)Flash Point: 76.66 °C; (19)Enthalpy of Vaporization: 43.854 kJ/mol; (20)Boiling Point: 220.718 °C at 760 mmHg; (21)Vapour Pressure: 0.17 mmHg at 25°C.

Preparation: this chemical can be prepared by azulene-1-carboxylic acid by heating. This reaction will need reagent CCl₃COOH and solvent benzene with the reaction time of 6 hours. The yield is about 90%.

Uses of Azulene: it can be used to produce 1,3-dibromo-azulene at the ambient temperature. It will need reagent NBS and solvent benzene with the reaction time of 2 hours. The yield is about 95%.

When you are using this chemical, please be cautious about it as the following:
This chemcial is toxic to aquatic organisms as it may cause long-term adverse effects in the aquatic environment. You must avoid releasing it to the environment, and you need to refer to special instructions/safety data sheet.

You can still convert the following datas into molecular structure:
(1)SMILES: c1cccc2cccc2c1
(2)Std. InChI: InChI=1S/C10H8/c1-2-5-9-7-4-8-10(9)6-3-1/h1-8H
(3)Std. InChIKey: CUFNKYGDVFVPHO-UHFFFAOYSA-N

The toxicity data is as follows: