Benzenesulfonic acid, 4-methyl-, compd. with pyridine (1:1) → (Racemic) 4-((tert-butyldiphenylsilyl)oxy)-7-(dimethoxymethyl)-1,2,3,4-tetrahydro-1,8-naphthyridine

Participants

Reaction Steps

A solution of 5-((tert-butyldiphenylsilyl)oxy)-5,6,7,8-tetrahydro-1,8-naphthyridine-2-carbaldehyde (intermediate 71, 300 mg, 0.720 mmol) in MeOH (10 ml) was treated with pyridinium p-toluenesulfonate (271 mg, 1.08 mmol) and heated to reflux for 16 h. The reaction mixture was allowed to cool to room temperature, treated with sat. aq. NaHCO3 and extracted with DCM (3×). The combined organic layers were washed with brine, dried over Na2SO4, filtered and concentrated under reduced pressure. The crude material was purified by normal phase chromatography (12 g silica gel cartridge, heptanes/EtOAc 100:0 to 40:60) to give the title compound as a colorless oil. (UPLC-MS 3) tR 1.42; ESI-MS 463.5 [M+H]+.

Provenance & Evidence