Diisopropylethylamine → 5-{2-[3-(2-Fluoro-ethoxy)-phenyl]-imidazo[1,2-a]pyrimidin-7-ylcarbamoyl}-1-methyl-1H-pyrazole-4-carboxylic acid ethyl ester

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Reaction Conditions

Reaction Steps

2-(3-(2-Fluoroethoxy)phenyl)imidazo[1,2-a]pyrimidin-7-amine (1 eq.) was combined with EtOAc (7.50 ml) to give a light yellow suspension. 4-(Ethoxycarbonyl)-1-methyl-1H-pyrazole-5-carboxylic acid (1 eq.) and DIPEA (6 eq.) were added. The reaction mixture was cooled down to 0° C. and n-propylphosphonic acid anhydride, cyclic trimer (1.17 g, 1.1 ml, 1.84 mmol, 2.50 eq.) was added dropwise. After stirring at 0° C. during 30 min, the reaction mixture was stirred and allowed to warm-up to RT overnight. The reaction mixture (yellow solution) was poured into 50 ml EtOAc and extracted with H2O (1×30 ml). The aqueous layer was back-extracted with DCM (3×20 ml). The organic layers were combined and washed with sat. NaCl-solution (1×30 ml), dried over MgSO4, filtrated and concentrated under vacuum to give a yellow solid (207 mg). The crude material was purified by flash chromatography (silica gel, 20 g, CH2Cl2 to 50% CH2Cl2/MeOH/NH3 aq. 140:10:1). Yellow solid (332 mg, 31%).

Provenance & Evidence