tert-Butyl 5-broMo-2H,3H-pyrrolo[2,3-b]pyridine-1-carboxylate synthesis

Yield:1111638-13-1 92%

Reaction Conditions:

with N-ethyl-N,N-diisopropylamine in N,N-dimethyl-formamide at 150; for 1.33333 h;

Steps:

1 Step 1: tert-Butyl-5-bromo-2,3-dihydro-7-aza indole-1-carboxylate

A mixture of 5-bromo-2,3-dihydro-7-aza-indole (0.40 g, 2.0 mmol, prepared from 2,3-dihydro-7-aza-indole according to the procedure described by Graczyk, P. et al., Synthesis of 5-Substituted 7-Azaindoles and 7-Azaindonines, PCT Int. App (2004), WO 2004078757), di-tert-butyl dicarbonate (0.52 g, 2.4 mmol) and N,N-diisopropylethylamine (0.30 mL, 2.2 mmol) in DMF (8 mL) was heated at 150°C for 1 h. Additional di-tert- butyl dicarbonate (0.05 g, 0.23 mmol) and DIEA (0.05 mL, 0.36 mmol) were added, and the mixture was heated at 150°C for an additional 20 min. The solvent was removed in vacuo, and water (10 mL) was added. The mixture was extracted with CH₂Cl₂, and the organic layer was washed with brine. The organic phase was then dried (Na₂SO₄), and the solvent was removed in vacuo. The residue was purified by FCC (SiO₂; elution with 0- 15% EtOAc/hexanes) to provide 0.55 g (92%) of tert-Butyl-5-bromo-2,3-dihydro-7-aza indole-1-carboxylate.LCMS (Method A): t_R= 0.82 min, m/z 299.3/301.2 (M+H)⁺.

References:

WO2017/214359,2017,A1 Location in patent:Page/Page column 90-91