Reaktion #720892

Reaktionsgleichung

hydrochloric acid

(S)-4-methyl-4-trifluoromethyl-4,5-dihydro-1H-imidazol-2-ylamine hydrobromide

sodium methoxide

diethyl malonate

→

(S)-7-hydroxy-2-methyl-2-trifluoromethyl-2,3-dihydro-1H-imidazo[1,2-a]pyrimidin-5-one

Ausbeute 107.5%

Lösungsmittel

methanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe resulting mixture is refluxed for 18 hours
2. 2
   TemperaturAfter cooling
3. 3
   Sonstigethe mixture obtained
4. 4
   Einengenis concentrated to dryness under vacuum
5. 5
   workup.ADDITION65 mL of cold water are added to the residue
6. 6
   Sonstigeobtained
7. 7
   Sonstigeto obtain a thick suspension
8. 8
   Filtrationfiltered
9. 9
   SonstigeThe insoluble matter obtained
10. 10
    Waschenis rinsed with water
11. 11
    Sonstigedried

Vorschrift

36.90 g (148.76 mmol) of (S)-4-methyl-4-trifluoromethyl-4,5-dihydro-1H-imidazol-2-ylamine hydrobromide and 24.10 g (446 mmol) of sodium methoxide are added to a mixture of 29.50 g (216.43 mmol) of diethyl malonate in 200 mL of methanol. The resulting mixture is refluxed for 18 hours. After cooling, the mixture obtained is concentrated to dryness under vacuum. 65 mL of cold water are added to the residue obtained, to obtain a thick suspension, to which is added 25% hydrochloric acid to pH 5. The resulting suspension is stirred in an ice bath for 3 hours and then filtered. The insoluble matter obtained is rinsed with water and then dried to give 37.60 g of (S)-7-hydroxy-2-methyl-2-trifluoromethyl-2,3-dihydro-1H-imidazo[1,2-a]pyrimidin-5-one in the form of a white solid, the characteristics of which are as follows:

Quelle