N,N-Diethylaniline → 2-Chloro-4,5,6-trimethylpyrimidine
Reaktionsgleichung
[CH3:1][C:2]1[C:7]([CH3:8])=[C:6]([CH3:9])[N:5]=[C:4](O)[N:3]=1.O=P(Cl)(Cl)[Cl:13].N(C1C=CC=CC=1)(CC)CC>>[Cl:13][C:4]1[N:3]=[C:2]([CH3:1])[C:7]([CH3:8])=[C:6]([CH3:9])[N:5]=1Komponenten
4
Versuchsvorschrift
To 4,5,6-trimethylpyrimidin-2-ol (3.69 g, 26.7 mmol) was added POCl3 (21.7 mL, 26.7 mmol) followed by Et2NPh (2.17 mL, 13.6 mmol) dropwise. The mixture was heated at reflux for 48 h and then added to ice dropwise. The aqueous layer was extracted with EtOAc (2×). Extraction was difficult due to a large amount of precipitate. The aqueous layer pH was adjusted to pH 4-5 with 28% NH4OH and was filtered through Celite®. The aqueous layer was then extracted with DCM and the combined organic extracts dried over Na2SO4, filtered and concentrated in vacuo to a yellow solid. Chromatography (FCC) (0 to 30% EtOAc/Hex) afforded 2-chloro-4,5,6-trimethylpyrimidine (4.26 g, 100%).