Benzyl Bromide → 5-benzyl-5-(4-bromophenyl)-5H-imidazo[2,1-a]isoindole

Participants

Reaction Conditions

Reaction Steps

To a solution of 5-(4-bromophenyl)-5H-imidazo[2,1-a]isoindole (5 g) in THF (100 mL) at −78° C. was added LAD solution (21.42 mL, 1.5 M in cyclohexane). After stirring for 15 minutes benzylbromide was added and the reaction mixture was stirred at −40° C. After 20 minutes more benzylbromide (3 mL) was added and continued to stir at −40° C. for 40 minutes. The reaction was then quenched with aqueous saturated NH4Cl and partitioned between aqueous saturated NH4Cl and EtOAc. Aqueous layer was extracted with EtOAc (2×). Combined organic layers were dried over Na2SO4 and concentrated. The resulting yellow solid was recrystallized from hot EtOAc to yield title compound as a white solid. HRMS. Found, 401.0647; calcd for (M+H)+, 401.0648. 1HNMR (500 MHz, CDCl3): δ 7.62 (d, J=7.1 Hz, 1H), 7.50 (d, J=8.6 Hz, 2H), 7.36 (dd, J=7.1, 0.9 Hz, 1H), 7.33-7.27 (m, 2H), 7.24 (s, 1H), 7.15 (d, J=8.3 Hz, 2H), 7.03 (t, J=7.8 Hz, 1H), 6.95 (t, J=7.8 Hz, 2H), 6.91 (s, 1H), 6.56 (d, J=7.6 Hz, 2H), 3.78 (s, 2H).

Provenance & Evidence