Potassium Acetate → 2,8-di(pyridin-3-yl)-5'H-spiro[chromeno[3,2-b]pyridine-10,4'-oxazol]-2'-amine

Participants

Reaction Conditions

Reaction Steps

A mixture of the 8-bromo-2-chloro-5′H-spiro[chromeno[3,2-b]pyridine-10,4′-oxazol]-2′-amine (from step 6, 40.0 mg, 0.109 mmol), potassium acetate (27.3 μL, 0.436 mmol), dichlorobis(triphenyl-phosphine)palladium (ii) (3.83 mg, 5.46 μmol) and 3-pyridylboronic acid (40.2 mg, 0.327 mmol) in 1.5 ml of dioxane/water=2:1 was heated at 110° C. under microwave irradiation for 15 min. LCMS and TLC showed incomplete conversion after 15 min. The reaction was re-heated in the microwave at 130° C. for 20 additional min. After cooling, the reaction mixture was purified by column chromatography (SiO2, DCM to DCM/MeOH=100:1 to 100:5 to 100:10 to 100:20) to afford 2,8-di(pyridin-3-yl)-5′H-spiro[chromeno[3,2-b]pyridine-10,4′-oxazol]-2′-amine as a gum. MS (M+1): 408.0; and 2-chloro-8-(pyridin-3-yl)-5′H-spiro[chromeno[3,2-b]pyridine-10,4′-oxazol]-2′-amine also as a gum. MS (M+1): 365.0.

Provenance & Evidence