Reaktion #471560

Reaktionsgleichung

sodium nitrite

5-(3-Amino-2-hydroxy-phenyl)-furan-2-carboxylic acid hydrobromide

5-(3-amino-2-hydroxy-phenyl)-furan-2-carboxylic acid hydrobromide

2-(3,3-dimethyl-indan-5-yl)-5-methyl-2,4-dihydro-pyrazol-3-one

sodium bicarbonate

→

5-(3-{N′-[1-(3,3-dimethyl-indan-5-yl)-3-methyl-5-oxo-1,5-dihydro-pyrazol-4-ylidene]-hydrazino}-2-hydroxy-phenyl)-furan-2-carboxylic acid

Ausbeute 40.3%

Lösungsmittel

hydrochloric acid

ethanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturupon cooling by an ice-water bath
2. 2
   SonstigeAfter the mixture was reacted for 20 minutes
3. 3
   SonstigeThe reaction mixture was reacted overnight at room temperature
4. 4
   FiltrationThe mixture was filtered
5. 5
   workup.ADDITION20 mL of water was added to the filter cake
6. 6
   FiltrationThe mixture was filtered
7. 7
   Sonstigethe filter cake was dried
8. 8
   Sonstigepurified by silica gel column chromatography

Vorschrift

5-(3-Amino-2-hydroxy-phenyl)-furan-2-carboxylic acid hydrobromide 9c (333 mg, 1.1 mmol) was dissolved in hydrochloric acid (3.7 mL, 1 mol/L) upon cooling by an ice-water bath, followed by dropwise addition of 1.5 mL of aqueous sodium nitrite (85 mg, 1.22 mmol). After the mixture was reacted for 20 minutes, 2-(3,3-dimethyl-indan-5-yl)-5-methyl-2,4-dihydro-pyrazol-3-one 8i (242 mg, 1.0 mmol), sodium bicarbonate (1.4 g, 16.67 mmol) and 3 mL of ethanol were added successively. The reaction mixture was reacted overnight at room temperature. The reaction was monitored by TLC until the disappearance of the starting materials. The mixture was filtered and 20 mL of water was added to the filter cake. The mixture was adjusted to pH 3˜4 with concentrated hydrochloric acid. The mixture was filtered and the filter cake was dried and purified by silica gel column chromatography to obtain the title compound 5-(3-{N′-[1-(3,3-dimethyl-indan-5-yl)-3-methyl-5-oxo-1,5-dihydro-pyrazol-4-ylidene]-hydrazino}-2-hydroxy-phenyl)-furan-2-carboxylic acid 43 (190 mg, yield 40.3%) as a red solid.

Quelle