Reaktion #471569

Reaktionsgleichung

sodium nitrite

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

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

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

sodium bicarbonate

→

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

Ausbeute 59.2%

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.ADDITIONthe filter cake was added to 20 mL of water
6. 6
   Temperaturupon cooling by an ice-water bath
7. 7
   FiltrationThe mixture was filtered
8. 8
   Waschenthe filter cake was washed with 6 mL of dichloromethane
9. 9
   Sonstigedried

Vorschrift

5-(3-Amino-2-hydroxy-5-methyl-phenyl)-furan-2-carboxylic acid hydrobromide 46c (219 mg, 0.70 mmol) was dissolved in 2.3 mL of 1 N hydrochloric acid upon cooling by an ice-water bath, followed by dropwise addition of 1.0 mL of aqueous sodium nitrite (53 mg, 0.77 mmol). After the mixture was reacted for 20 minutes, 2-indan-5-yl-5-methyl-2,4-dihydro-pyrazol-3-one 1i (134 mg, 0.63 mmol), sodium bicarbonate (878 mg, 10.45 mmol) and 2 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 the filter cake was added to 20 mL of water. The mixture was adjusted to pH 3˜4 with concentrated hydrochloric acid upon cooling by an ice-water bath. The mixture was filtered and the filter cake was washed with 6 mL of dichloromethane and dried to obtain the title compound 5-{2-hydroxy-3-[N′-(1-indan-5-yl-3-methyl-5-oxo-1,5-dihydro-pyrazol-4-ylidene)-hydrazino]-5-methyl-phenyl}-furan-2-carboxylic acid 46 (170 mg, yield 59.2%) as a red solid.

Quelle