Yield:1022150-57-7 64%

Reaction Conditions:

with N-ethyl-N,N-diisopropylamine;tris-(dibenzylideneacetone)dipalladium⁽⁰⁾;4,5-bis(diphenylphosphino)-9,9-dimethylxanthene in N,N-dimethyl acetamide at 100; for 22 h;Product distribution / selectivity;

Steps:

4.b

Method b; [0358] A solution of 6-bromoquinoline (550 mg, 2.64 mmol), diisopropylethylamine (1.13 niL, 6.46 mmol) in DMA (4 mL) under nitrogen was degassed by bubbling in nitrogen for 20 min. Tris(dibenzylideneacetone)dipalladium (105 mg, 0.108 mmol, Strem catalyst), Xantphos (125 mg, 0.216 mmol), and 6-(l-methyl-lH-pyrazol-4-yl)-[l,2,4]triazolo[4,3- ]pyridazine-3 -thiol (500 mg, 2.155 mmol) were added under a stream of nitrogen. The reaction mixture was stirred at 100⁰C for 22h, with disappearance of the solid suspension. The reaction mixture was cooled to room temperature and filtered through a plug of silica gel, using DMF as eluent. The organics were then directly poured onto ice/water mixture and left standing for 15 min. The precipitate was filtered and washed with water. The resulting cake was grinded in diethyl ether, filtered, and dried in vacuo to yield 770 mg of a yellow solid. The solid was stirred in refluxing isopropanol for Ih, filtered, washed with isopropanol, and dried in a vacuum oven at 7O⁰C for 3 days to provide 500 mg of 6-[6-(l- methyl-lH-pyrazol-4-yl)-[l,2,4]triazolo[4,3-6]pyridazin-3-ylsulfanyl]-quinoline as a yellow solid with 8% impurity (64% yield).

References:

WO2008/51808,2008,A2 Location in patent:Page/Page column 101