Sodium hydride → 2-Bromo-6-(4-methoxy-phenyl)-4-(2-trimethylsilanyl-ethoxymethyl)-4,7-dihydro-1-thia-4,5-diaza-cyclopenta[a]pentalene

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Reaction Conditions

Reaction Steps

At 0° C., NaH (60 percent, 1.3 g, 33 mmol) was added to a THF solution (40 mL) containing 2-Bromo-6-(4-methoxy-phenyl)-4,7-dihydro-1-thia-4,5-diaza-cyclopenta[a]pentalene (8.3 g, 24 mmol). Then SEM-Cl (5.6 mL, 28 mmol) was added to the reaction mixture and the resulting mixture was stirred at 0° C. for 30 min, warmed up to 80° C. and stirred for 2 hr. The solution was cooled to room temperature and poured into ice water. The resulting mixture was extracted with ethyl acetate. The organic layer was collected and washed with saturated aqueous NH4Cl, dried over MgSO4(s), and concentrated under reduced pressure. The oily residue was purified by gravity column chromatography (20% ETOAc in hexane) to give 2-Bromo-6-(4-methoxy-phenyl)-4-(2-trimethylsilanyl-ethoxymethyl)-4,7-dihydro-1-thia-4,5-diaza-cyclopenta[a]pentalene (9.0 g, 18 mmol) as brown solid in 79% yield.

Provenance & Evidence