4-(6-CHLORO-PYRIDAZIN-3-YL)-PIPERAZINE-1-CARBOXYLIC ACID TERT-BUTYL ESTER

Synthesis of tert-butyl 4-(6-chloropyridazin-3-yl)piperazine-1-carboxylate A solution of 3, 6-dichloropyridazine (5.01 g, 33.6 mmol) and tert-butyl piperazine-1-carboxylate (6.88g, 37.0 mmol) in DMF (50 mL) was added triethylamine (11.7 mL, 50.4 mmol) and stirred at 80°C overnight. The resultant reaction mixture was cooled to room temperature, and water was added to the mixture. The mixture was extracted three times with a solvent mixture of dichloromethane and methanol (95:5) (50 mL). The resultant organic phases were combined together and dried over anhydrous magnesium sulfate. The resultant solid was separated by filtration, and the filtrate was then concentrated under reduced pressure. The resultant crude product was washed with diethyl ether to yield the title compound (7.0 g, 70percent).Preparation of tert-Butyl 4-(6-chloropyridazin-3-yl)piperazine-1-carboxylate 6-3: (1202) (1203) A stirred mixture of 3, 6-dichloropyridazine 6-1 (2.0 g, 13.4 mmol), tert-butyl piperazine- 1-carboxylate 6-2 (3.72 g, 20.0 mmol) and triethylamine (2.78 mL, 20.0 mmol) in toluene (20mL) was heated at 110 °C for 16 h. After complete consumption of 6-1 as evident from TLC, the volatiles were stripped off, residue partitioned between ethyl acetate and water, combined organic extracts evaporated to afford a crude residue which was purified column chromatography (elution with 30percent ethyl acetate/Hexane) to afford tert-butyl 4-(6-chloropyridazin-3- yl)piperazine-1-carboxylate 6-3 (2.52 g, 8.46 mmol, 63.0 percent) as an off-white solid. LC MS: ES+ 299.2

Molecular Weight:298.77
XLogP3:1.9
Hydrogen Bond Acceptor Count:5
Rotatable Bond Count:3
Exact Mass:298.1196536
Monoisotopic Mass:298.1196536
Topological Polar Surface Area:58.6
Heavy Atom Count:20
Complexity:340
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes