Formaldehyde → Methyl (2s,3s,5s)-1-methyl-2-[(4-phenyl-3,6-dihydropyridin-1(2h)-yl)carbonyl]-5-(pyridin-4-yloxy)piperidine-3-carboxylate

Participants

Reaction Steps

1-tert-butyl 3-methyl (2S,3S,5S)-2-[(4-phenyl-3,6-dihydropyridin-1(2H)-yl)carbonyl]-5-(pyridin-4-yloxy)piperidine-1,3-dicarboxylate (0.09 g, 0.0002 mol) was treated with trifluoroacetic acid (1.0 mL, 0.013 mol) at rt for 1 h. The mixture was then concentrated to dry. The crude secondary amine made above was dissolved in tetrahydrofuran (0.80 mL, 0.0099 mol) and acetonitrile (0.80 mL, 0.015 mol). The mixture was then treated with N,N-diisopropylethylamine (0.061 mL, 0.00035 mol) to adjust the pH to around 7. To the resultant mixture was then added 12.32 M of formaldehyde in water (0.071 mL) followed by sodium triacetoxyborohydride (180 mg, 0.00087 mol). After stirred at rt overnight, the mixture was concentrated to dry in vacuo, diluted with aq. sodium bicarbonate, extracted with EtOAc. The combined organic layers were washed with brine, dried, and evaporated to dry in vacuo. The residue was exposured in high vacuum and then used directly in next step. MS (ESI): (M+H)+=436.1.

Provenance & Evidence