3-benzyl-4-oxo-4H-pyrido[1,2-a]pyrimidine-2-carbaldehyde → 3-benzyl-2-(1-hydroxyprop-2-enyl)-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one

Participants

Reaction Conditions

Reaction Steps

A mixture of 2.5 g (9.5 mmol) of the product from Step 6 (16) in 35 mL THF was cooled to −78° C. To the resulting solution was added dropwise 11.4 mL (11.4 mmol) of vinyl magnesium bromide and stirred at −78° C. for 3 hours. The reaction was quenched with saturated NH4Cl and extracted with ethyl acetate (4×). The combined organic layers were dried over MgSO4 and the solvent was removed in vacuo yielding 2.95 g of 3-benzyl-2-(1-hydroxyprop-2-enyl)-6,7,8,9-tetrahydro-4H-pyrido[1,2-a]pyrimidin-4-one (23) as a yellow oil.

Provenance & Evidence