ChemicalBook CAS DataBase List 4-BROMO-7-METHOXY-1H-INDOLE

4-BROMO-7-METHOXY-1H-INDOLE synthesis

6synthesis methods

Product Name:4-BROMO-7-METHOXY-1H-INDOLE
CAS Number:436091-59-7
Molecular formula:C9H8BrNO
Molecular Weight:226.07

1-BroMo-4-Methoxy-2-Methyl-3-nitrobenzene

85598-13-6
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4637-24-5 Synthesis

4637-24-5
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436091-59-7
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Yield:436091-59-7 44%

Reaction Conditions:

Stage #1:1-bromo-4-methoxy-2-methyl-3-nitro-benzene;N,N-dimethyl-formamide dimethyl acetal with pyrrolidine in N,N-dimethyl-formamide at 90; for 18 h;
Stage #2: with iron;acetic acid for 1 h;Reflux;
Stage #3: with sodium carbonate in water

Steps:

B-5.3 Step 3 Preparation of 4-bromo-7-methoxyindole:
To a solution of 1-bromo-4-methoxy-2-methyl-3-nitro-benzene (31 g, 0.126 mol) in DMF (150 mL) was added dimethylformamide dimethylacetal (27 mL) and pyrrolidine (10.5mL, 0.127 mol). The mixture was heated at 90°C for 18h and cooled to r.t. The mixture was diluted with water and extracted with CH₂CI₂. The organic phase was dried over Na₂S0_4i filtered and concentrated. The residue was dissolved into HOAc (50 mL) and added dropwise to a solution of Fe (20.5 g, 0.37 mol) in boiling HOAc (150 mL). The mixture was refluxed for 1h and cooled to r.t., water added and the mixture was neutralised with Na₂C0₃, and extracted with CH₂CI₂.The organic phase was dried over Na₂S0₄, filtered and concentrated. The residue was purified by Prep-TLC (PE/EtOAc =5/1) to give the title compound (13 g, 44%). H NMR CDCI₃400 MHz δ: 8.41 (brs, 1 H), 7.18-7.08 (m, 2H), 6.49-6.43 (m, 2H), 3.86 (s, 3H).