The 3(2H)-Pyridazinone,4,5-dichloro-2-methyl-, with the CAS registry number 933-76-6, has the systematic name of 4,5-dichloro-2-methylpyridazin-3(2H)-one. It is a kind of off-white to yellow low crystalline powder, and belongs to thefollowing  product categories: Halides; Pyrazines, Pyrimidines & Pyridazines; Pyrazines, Pyrimidines & Pyridazines. And the molecular formula of the chemical is C₅H₄Cl₂N₂O.

The characteristics of 3(2H)-Pyridazinone,4,5-dichloro-2-methyl- are as followings: (1)ACD/LogP: -0.34; (2)# of Rule of 5 Violations: 0; (3)ACD/LogD (pH 5.5): -0.34; (4)ACD/LogD (pH 7.4): -0.34; (5)ACD/BCF (pH 5.5): 1; (6)ACD/BCF (pH 7.4): 1; (7)ACD/KOC (pH 5.5): 15.65; (8)ACD/KOC (pH 7.4): 15.65; (9)#H bond acceptors: 3; (10)#H bond donors: 0; (11)#Freely Rotating Bonds: 0; (12)Polar Surface Area: 32.67 Å²; (13)Index of Refraction: 1.611; (14)Molar Refractivity: 39.91 cm³; (15)Molar Volume: 114.8 cm³; (16)Polarizability: 15.82×10^-24cm³; (17)Surface Tension: 47.9 dyne/cm; (18)Density: 1.55 g/cm³; (19)Flash Point: 73.1 °C; (20)Enthalpy of Vaporization: 43.34 kJ/mol; (21)Boiling Point: 197.2 °C at 760 mmHg; (22)Vapour Pressure: 0.382 mmHg at 25°C.     

Uses of 3(2H)-Pyridazinone,4,5-dichloro-2-methyl-: It can react with 2-methylamino-ethanol to produce 4-chloro-5-[(2-hydroxy-ethyl)-methyl-amino]-2-methyl-2H-pyridazin-3-one. This reaction will need reagent ethanol and methanol. The reaction time is 3 hours with heating, and the yield is about 73%.

You should be cautious while dealing with this chemical. It irritates to eyes, respiratory system and skin. It is also harmful if swallowed, and may cause sensitization by skin contact. Therefore, you had better take the following instructions: Wear suitable protective clothing, and if in case of contacting with eyes, rinse immediately with plenty of water and seek medical advice.

Addtionally, the following datas could be converted into the molecular structure:
(1)SMILES: Cl\C1=C(/Cl)\C=N/N(C1=O)C
(2)InChI: InChI=1/C5H4Cl2N2O/c1-9-5(10)4(7)3(6)2-8-9/h2H,1H3
(3)InChIKey: ACKBTCUMGAHRIE-UHFFFAOYAN

The toxicity data is as follows: