Dimethylformamide → 2-(Dimethoxymethyl)-5,6,7,8-tetrahydro-1,8-naphthyridine-3-carbaldehyde

Participants

Reaction Steps

To a solution of 6-bromo-7-(dimethoxymethyl)-1,2,3,4-tetrahydro-1,8-naphthyridine (intermediate 12, 15.0 g, 52.2 mmol) in THF (400 ml) at −78° C. under argon, was added MeLi (1.6 M in Et2O, 32.6 ml, 52.2 mmol), the solution was stirred for 5 min, then n-BuLi (1.6 M in hexane, 35.9 ml, 57.5 mmol) was added slowly and the solution was stirred for 20 min. THF (100 ml) was added to the reaction at −78° C. Subsequently, n-BuLi (1.6 M in hexane, 49.0 ml, 78 mmol) was added and the reaction mixture was stirred for 20 min, then again n-BuLi (1.6 M in hexane, 6.53 ml, 10.45 mmol) was added and the mixture was stirred for 10 min at −78° C. DMF (2.10 ml, 27.2 mmol) was added and the reaction mixture was stirred at −78° C. for 45 min, then it was allowed to warm to room temperature, poured into sat. aq. NH4Cl and extracted twice with DCM. The combined organic phases were dried over Na2SO4, filtered and evaporated to give the title compound as an orange oil. (UPLC-MS 3) tR 0.63 min; ESI-MS 237.2 [M+H]+.

Provenance & Evidence