Reaktion #72880

Reaktionsgleichung

ethyl 8-amino-1-methyl-1H-pyrazolo[4,3-h]quinazoline-3-carboxylate

trichloroacetylisocyanate

→

title compound

Ausbeute 34.4%

Ethyl 8-[(aminocarbonyl)amino]-1-methyl-1H-pyrazolo[4,3-h]quinazoline-3-carboxylate

Ausbeute 34.4%

Lösungsmittel

pyridine

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe solvent was then evaporated under reduced pressure
2. 2
   workup.ADDITIONthe residue was treated with 50 mL of methanol
3. 3
   workup.STIRRINGAfter 2 hours under stirring the solvent
4. 4
   Sonstigewas removed
5. 5
   workup.DISSOLUTIONthe residue redissolved with dichloromethane
6. 6
   Waschenwashed with a diluted solution of ammonium hydrate
7. 7
   TrocknenAfter drying over anhydrous Na2SO4 the organic layer
8. 8
   Sonstigewas evaporated to dryness
9. 9
   Sonstigethe residue purified by chromatography on a silica gel column (eluant: dichloromethane/acetone 4/1)

Vorschrift

1.00 g (3.7 mmol) of ethyl 8-amino-1-methyl-1H-pyrazolo[4,3-h]quinazoline-3-carboxylate were dissolved in 50 mL of pyridine and 1 mL (8.0 mmol) of trichloroacetylisocyanate were added. The mixture was stirred overnight at room temperature. The solvent was then evaporated under reduced pressure and the residue was treated with 50 mL of methanol. After 2 hours under stirring the solvent was removed, the residue redissolved with dichloromethane and washed with a diluted solution of ammonium hydrate. After drying over anhydrous Na2SO4 the organic layer was evaporated to dryness and the residue purified by chromatography on a silica gel column (eluant: dichloromethane/acetone 4/1) leading 0.40 g (34% yield) of the title compound.

Quelle