[Cl:1][C:2]1[CH:7]=[C:6]([CH:8]=[CH2:9])[N:5]=[C:4]([CH3:10])[N:3]=1.[N+](=[CH:13][C:14]([O:16][CH2:17][CH3:18])=[O:15])=[N-]>C1(C)C=CC=CC=1>[Cl:1][C:2]1[N:3]=[C:4]([CH3:10])[N:5]=[C:6]([CH:8]2[CH2:9][CH:13]2[C:14]([O:16][CH2:17][CH3:18])=[O:15])[CH:7]=1A solution of 4-chloro-2-methyl-6-vinylpyrimidine (4-1, 15.0 g, 97 mmol 1.0 eq) in Toluene (300 mL) was heated to 100° C. under a nitrogen atmosphere. A solution of ethyl diazoacetate (30.2 mL, 291 mmol, 3.0 eq) was added as a solution in toluene (100 mL) over 1.5 hours. Heating was continued for 2 hours. The reaction mixture was allowed to cool to room temperature and concentrated to dryness. The residue was partitioned between saturated sodium bicarbonate solution (1 L) and ethyl acetate (1 L). The organic layer was separated, dried over sodium sulfate, filtered and concentrated to dryness. The resulting residue was purified by silica gel column chromatography (0-100% ethyl acetate in hexanes) to give ethyl 2-(6-chloro-2-methylpyrimidin-4-yl)cyclopropanecarboxylate (4-2) as a colorless oil.
Wird geladen…