Ammonium Chloride → 1-(Tert-butyl) 3-methyl 4-(4-(2-((tert-butyldimethylsilyl)oxy)ethoxy)phenyl)-5,6-dihydropyridine-1,3(2h)-dicarboxylate

Participants

Reaction Conditions

Reaction Steps

To a sol. of 4-[2-(tert-butyldimethylsilanyloxy)ethoxy]bromobenzene (WO 03/093267, 7.95 g, 24 mmol) in THF (200 mL) at −78° C. was added BuLi (1.6M in hexane, 17.12 mL, 27.4 mmol). The sol. was stirred at −78° C. for 30 min, then ZnCl2 (1M in THF, 30 mL, 30 mmol) was added. The resulting sol. was allowed to warm to rt, and 4-trifluoromethanesulfonyloxy-5,6-dihydro-2H-pyridine-1,3-dicarboxylic acid 1-tert-butyl ester 3-methyl ester (WO 2004/002957, 7.79 g, 20 mmol) in THF (20 mL) and Pd(PPh3)4 (0.69 g, 0.60 mmol) were added. The reaction mixture was heated to 50° C. for 1 h, and stirred 16 h at rt. The mixture was cooled to 0° C., and aq. sat. NH4Cl was added. EtOAc was added, and the org. phase was washed with brine, dried over MgSO4, filtered, and the solvents were removed under reduced pressure. Purification of the residue by FC (EtOAc/heptane 2:8→1:0) yielded the title compound (8.1 g, 82%). LC-MS: tR=1.23 min, ES+: 506.47.

Provenance & Evidence