O[CH2:2][CH2:3][C:4]1[CH:9]=[N:8][CH:7]=[CH:6][N:5]=1.C(Br)(Br)(Br)[Br:11].C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1>ClCCl>[Br:11][CH2:2][CH2:3][C:4]1[CH:9]=[N:8][CH:7]=[CH:6][N:5]=1To a solution of 2-(2′-hydroxyethyl)pyrazine (0.91 g) in 30 mL dichloromethane at 0° C. was added carbon tetrabromide (2.65 g) followed by triphenylphosphine (2.1 g) portionwise. The solution became very dark. After stirring for 1 h the reaction mixture was adsorbed onto HMN diatomaceous earth and purified by silica gel chromatography eluting with 0-5% MeOH/dichloromethane to give a cream solid (3.07 g) that was purified further by silica gel chromatography eluting with 0-50% EtOAc/pentane to give the sub-titled compound (0.47 g, 34%) as a yellow oil.
Wird geladen…