Phosphorus oxychloride → 2-Methyl-5-propyl-6-chloro-pyrimidine-4-carboxylic acid ethyl ester
Reaktionsgleichung
[CH2:1]([O:3][C:4]([C:6]1[C:11]([CH2:12][CH2:13][CH3:14])=[C:10](O)[N:9]=[C:8]([CH3:16])[N:7]=1)=[O:5])[CH3:2].O=P(Cl)(Cl)[Cl:19]>>[CH2:1]([O:3][C:4]([C:6]1[C:11]([CH2:12][CH2:13][CH3:14])=[C:10]([Cl:19])[N:9]=[C:8]([CH3:16])[N:7]=1)=[O:5])[CH3:2]Komponenten
3
Reaktionsbedingungen
- Temperatur
- 85 °C
Versuchsvorschrift
A mixture of 2-methyl-5-propyl-6-hydroxy-pyrimidine-4-carboxylic acid ethyl ester (10 mmol) and POCl3 (25 mL) is heated at 85° C. for 4 hours. The solvent is removed in vacuo and EtOAc (40 mL) and water (30 mL) are added to the residue. NaHCO3 is carefully added until the pH of aqueous layer is greater than 7. The layers are separated and the aqueous layer is extracted with EtOAc (2×30 mL). The combined extracts are washed with brine (50 mL), dried (Na2SO4), and evaporated. Flash column purification of the residue with 3:1 EtOAc, hexane provides 2-methyl-5-propyl-6-chloro-pyrimidine-4-carboxylic acid ethyl ester as a light yellow oil. Step 4. Preparation of 2-Methyl-5-propyl-4-chloromethyl-6-chloro-pyrimidine