Trimethylaluminum → 3-Bromo-7-iodo-2',6'-dihydrospiro[chromeno[2,3-b]pyridine-5,3'-[1,4]oxazin]-5'-amine

Participants

Reaction Steps

A solution of 2-((5-amino-3-bromo-7-iodo-5H-chromeno[2,3-b]pyridin-5-yl)methoxy)acetonitrile (5.58 g, 11.82 mmol) in 100 mL 2-MeTHF under nitrogen atmosphere was treated with trimethylaluminum [2N in heptane (7.98 mL, 15.96 mmol)]. After stirring for 10 minutes at RT, the reaction mixture was heated to 80° C. for 90 minutes. The reaction mixture was cooled to RT and quenched with MeOH. The reaction mixture was treated with saturated Rochelle's salt solution and vigorously stirred for an additional hour. The organic layer was separated, washed with brine, dried over MgSO4 and concentrated under reduced pressure. Purification of the crude residue by column chromatography [0-80% (90:10:1 DCM/MeOH/NH4OH)/DCM] gave 3-bromo-7-iodo-2′,6′-dihydrospiro[chromeno[2,3-b]pyridine-5,3′-[1,4]oxazin]-5′-amine (Intermediate 2, 2.97 g).

Provenance & Evidence