ethyl 5-amino-1-methyl-1H-indole-2-carboxylate synthesis

Yield:71056-58-1 77%

Reaction Conditions:

with palladium 10% on activated carbon;hydrogen in methanol at 20; for 12 h;

Steps:

1-2; 24-2; 227-2 Example 1-2
Synthesis of ethyl 5-amino-1-methyl-1H-indole-2-carboxylate


Ethyl 1-methyl-5-nitro-1H-indole-2-carboxylate (2.38 g, 9.58 mmol) was added to a 100 mL flask and dissolved in MeOH (50 ml).
10% Pd/C (2.3 g) was added and stirred for 12 hours at room temperature under H₂ (g).
After Celite filtration upon completion of the reaction, the solvent was removed by distillation under reduced pressure.
The residue was subjected to column chromatography (ethyl acetate:n-hexane=1:3) to obtain ethyl 5-amino-1-methyl-1H-indole-2-carboxylate (1.66g, 7.60 mmol, 77%).
1H NMR (300 MHz, CDCl₃) 7.52 (s, 1H), 7.21-7.18 (m, 1H), 7.09 (s, 1H), 6.92-6.91 (m, 1H), 6.85-6.82 (m, 1H), 4.38-4.31 (m, 2H), 4.01 (s, 3H), 3.55 (br, NH, 2H), 1.42-1.37 (m, 3H).

References:

EP4023638,2022,A1 Location in patent:Paragraph 0058; 0060-0061; 0112; 0114-0115; 0628; 0630-0631