1-Methylpiperazine → 5-(4-Methylpiperazin-1-yl)-1H-indole

Participants

Reaction Conditions

Reaction Steps

5-Bromo-1-triisopropylsilyl-indole (5.8 g, 16.4 mmol), N-methylpiperazine (1.8 g, 18 numol), NaOt-Bu (2.2 g, 23 mmol), Pd(OAc)2 (37 mg, 0.16 mmol), Pt-Bu3 (66 mg, 0.33 nmmol) and xylene (30 mL) were mixed and heated to 130° C. under stirring for 5 h. The crude material was chromatographed on a silica column using DCM/MeOH 95/5 as eluent. Concentration of the main fractions left 5.6 g of an oil which was dissolved in MeCN (10 mL), 20 mL of a 1 M solution of tetrabutylammonium fluoride in THF was added and the mixture left over-night. The reaction mixture was put on a silica column and eluted with DCM/MeOH 95/5 to give the product as an oil (2 g, 9.3 mmol; yield 57 %) 1H NMR (CDCl3) δ 2.37 (3 H, s), 2.64 (4 H, t, J=5), 3.19 (4 H, t, J=5), 6.44–6.48 (1 H, m), 6.95–7.00 (1 H, m), 7.16 (1 H, d, J=3), 7.18 (1 H, d, J=2), 7.29 (1H, d, J=9) and 8.12 (1 H, bs).

Provenance & Evidence