ChemicalBook CAS DataBase List 4-HYDROXY-1H-INDOLE-3-CARBALDEHYDE

4-HYDROXY-1H-INDOLE-3-CARBALDEHYDE synthesis

5synthesis methods

Product Name:4-HYDROXY-1H-INDOLE-3-CARBALDEHYDE
CAS Number:81779-27-3
Molecular formula:C9H7NO2
Molecular Weight:161.16

2380-94-1

68-12-2

81779-27-3

Example 1: Synthesis of 4-hydroxy-1H-indole-3-carbaldehyde 1. 7.35 mL of phosphorus oxychloride was slowly added dropwise to 15 mL of dry N,N-dimethylformamide under cooling conditions in an ice-methanol bath with stirring for 15 minutes. 2. 5.0 g of 4-hydroxyindole dissolved in 10 mL of anhydrous N,N-dimethylformamide was added slowly dropwise to the above mixture under cooling in an ice bath. 3. The reaction mixture was stirred at room temperature for 2 hours. 4. Under cooling in an ice bath, water was added to the reaction mixture and adjusted to alkaline with 30% aqueous sodium hydroxide solution and stirring was continued for 15 minutes. 5. The mixture was acidified to pH 4 with 5N hydrochloric acid and the precipitate was collected by filtration. 6. The precipitate was washed with water and dried to give 4.99 g of 4-hydroxy-1H-indole-3-carbaldehyde crude product in 82% yield. 7. The crude product was recrystallized with methanol to give yellow crystals. Product characterization. 1H-NMR (DMSO-d6) δ: 6.54 (1H, dd, J = 8.1, 0.9 Hz), 6.95 (1H, dd, J = 8.1, 0.9 Hz), 7.13 (1H, t, J = 8.1 Hz), 8.37 (1H, s), 9.64 (1H, s), 10.54 (1H, br s), 12.35 (1H, br s). br s). Melting point: 190-193 °C.

2380-94-1
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$8.00/250mg

81779-27-3
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$43.00/250mg

Yield:-

Reaction Conditions:

with sodium hydroxide;trichlorophosphate in N-methyl-acetamide;water

Steps:

1 4-Hydroxyindole-3-carbaldehyde(1-1) (R7=R11=H)
4-Hydroxyindole-3-carbaldehyde(1-1) (R⁷=R¹¹=H) Phosphorous oxychloride 7.35 ml was added dropwise to dry dimethylformamide 15 ml under cooling in ice-methanol bath and the mixture was stirred for 15 min. Then, a solution of the 4-hydroxyindole 5.0 g in dry dimethylformamide 10 ml was added dropwise to the mixture under cooling in ice and the mixture was stirred for 2 h at room temperature. Water was added under cooling in ice to the mixture, which was made alkaline with a 30% aqueous sodium hydroxide solution and was stirred for 15 min. Then, the mixture was acidified to pH 4 with 5N-HCl and the precipitate was collected by filtration, washed with water and dried to give the titled compound 4.99 g as crude crystalline materials. Yield 82%. Crude crystalline materials are recrystallized from methanol to give yellow crystals m.p. 190-193 ØC. ¹H-NMR(DMSO-d₆): 6.54 (1H, dd, J = 8.1, 0.9 Hz), 6.95 (1H, dd, J = 8.1, 0.9 Hz), 7.13 (1H, t, J = 8.1 Hz), 8.37 (1H, s), 9.64 (1H, s), 10.54 (1H, br s), 12.35 (1H, br s).

References:

SHIONOGI & CO., LTD. EP1325909, 2003, A1

7042-71-9 Synthesis