TERT-BUTYL 4-(5-BROMO-1H-INDOL-3-YL)-3,6-DIHYDRO-1(2H)-PYRIDINECARBOXYLATE synthesis

Yield:886361-90-6 86%

Reaction Conditions:

with sodium methylate in methanol at 80; for 48 h;

Steps:

9.A

To a solution of commercially available 5-bromoindole (3.5 g, 17.9 mmol) in methanol (50 mL) was added 1-Boc-4-piperidone (5.1 g, 25.6 mmol) and a solution of 25% sodium methoxide in methanol (8 mL, 37 mmol) and the reaction mixture was heated at 80° C. for 2 days. The reaction mixture was filtered off. The solid was washed twice with ethyl acetate and dried under vacuum to give the title compound (3 g). The filtrate was diluted with ethyl acetate (250 mL) and washed with water, brine and dried over Na₂SO₄. The solvent was removed under reduced pressure to yield the crude product, which was purified on a silica gel column to afford additional title compound (2.9 g). The combined yield was 5.9 g, 86%.¹H-NMR (400 MHz, CDCl₃): δ=1.52 (s, 9H), 2.55 (m, 2H), 3.69 (t, 2H), 4.16 (s, 2H), 6.12 (s, 1H), 7.19 (s, 1H), 7.26-7.33 (m, 2H), 8.01 (s, 1H), 8.29 (br-s, 1H)

References:

US2011/280808,2011,A1 Location in patent:Page/Page column 44