5-Bromo-2,4-bis(1,1-dimethylethoxy)pyrimidine → (+/-)-4-(2,4-Bis(1,1-dimethylethoxy)pyrimidin-5-yl)-7-ethyl-2-methyl-9,10-dihydro-4H-benzo[5,6]cyclohepta[1,2-d]oxazol-4-ol

Beteiligte Stoffe

Reaktionsschritte

A stirred solution of the product from example 1 step (vi) (3.60 g) in tetrahydrofuran (30 ml) at −70° C. was treated dropwise with n-butyllithium (4.75 ml of a 2.5M solution in hexanes) and stirred for 30 minutes. A solution of the product from example 3 step (vi) (2.60 g) in tetrahydrofuran (30 ml) was added dropwise and the reaction stirred at room temperature for 3 hours. The reaction was partitioned between brine and ethyl acetate and the organics dried (MgSO4) and evaporation under reduced pressure gave a brown oil. Purification was by column chromatography eluting with 50% ethyl acetate in isohexane.

Herkunft & Nachweise