Acetic Acid → 2-(Benzhydryl-amino)-3-hydroxy-3-(6-methoxy-[1,5]naphthyridin-4-yl)-propionic acid methyl ester

Participants

Reaction Steps

A mixture of Zn(OTf)2 (0.064 g, 0.17 mmol) and 6-methoxy-[1,5]naphthyridine-4-carbaldehyde (0.5 g, 2.6 mmol) and molecular sieves (4 Å, 0.66 g) in toluene (13 mL) at 0° C. was treated with (benzhydrylidene-amino)-acetic acid methyl ester (0.44 g, 1.7 mmol) and diallylamine (0.25 g, 1.7 mmol). The mixture was left at 4° C. over the weekend. The reaction was quenched by careful addition of Na2CO3 and filtered. The filtrate was diluted with EA and water and the 2 phases separated. The org. phase was dried over MgSO4 and concentrated. The residue was dissolved in MeOH (10 mL) and AcOH (0.175 g, 3 mmol) and NaCNBH3 (0.166 g, 2.6 mmol) was added. The mixture was stirred at rt overnight and partitioned between a NaHCO3 solution and EA. The org. phase was dried over MgSO4 and concentrated. Chromatography on SiO2 (Hex/EA 1:1) gave the title intermediate as a yellow oil (0.5 g, 64% yield).

Provenance & Evidence