6-Chloro-imidazo[1,2-b]pyridazin-8-ylamine synthesis

Yield:1161847-36-4 100%

Reaction Conditions:

Stage #1: (6-chloroimidazo[1,2-b]pyridazin-8-yl)carbamic acid tert-butyl esterwith trifluoroacetic acid in dichloromethane; for 5 h;
Stage #2: with sodium hydrogencarbonate in dichloromethane;water;

Steps:

12

Example 12.; A solution of (6-chloro-imidazo[l,2-b]pyridazin-8-yl)-carbamic acid tert-butyl ester (1.59 g, 5.91 mmol) in 30 mL of dichloromethane and 15 mL of trifluoro acetic acid was stirred for 5 h then concentrated to a yellow oil, which was treated (slowly) with 50 mL of a saturated aq. NaHCOs solution. Undissolved solid was isolated by Buchner filtration, rinsing well with water and dried by sucking air through then in vacuo to afford 1.10 g (102% crude) of 6-chloro-imidazo[l,2-b]pyridazin-8-ylamine as a yellow solid that was used without further purification.

References:

WO2009/77334,2009,A1 Location in patent:Page/Page column 85