1,4-Dioxane → HCID 67394324, compound

Participants

Reaction Conditions

Reaction Steps

A 500 mL round bottom flask was charged with tert-butyl 4-(8-bromotetrazolo[1,5-c]pyrimidin-5-yl)piperazine-1-carboxylate (5.5 g, 14.3 mmol), thiophene-2-boronic acid (2.5 g, 21.5 mmol), tetrakis(triphenylphosphine)palladium(0) (2.0 g, 1.43 mmol), potassium tert-butoxide (2.4 g, 21.5 mmol), 1,4-dioxane (200 mL) and water (50 mL). After the air was purged by bubbling N2 into the solution, the resulting mixture was stirred at 80° C. under N2 for 10 h. Work-up: the reaction mixture was diluted with 0.1 M HCl (20 mL) and washed with EtOAc (150 mL×3). The aqueous layer was then basified with solid NaHCO3 and extracted with CH2Cl2 (150 mL×3). The combined CH2Cl2 layers were dried over anhydrous Na2SO4 and concentrated in vacuo. The residue was purified by flash column chromatography on silica gel with 1-10% MeOH in CH2Cl2 to afford 0.70 g (12%) of the product, and 0.45 g (8.7%) of tert-butyl 4-(4-amino-5-(thiophen-2-yl)pyrimidin-2-yl)piperazine-1-carboxylate.

Provenance & Evidence