Sodium hydride → 3-(4-fluoro-phenyl)-4H,6H-1,2,5,10b-tetraaza-benzo[e]azulene-5-carboxylic acid tert-butyl ester

Participants

Reaction Steps

Sodium hydride (80.0 mg, 2.0 mmol; 60% suspension in mineral oil) was washed with hexane (2 mL) in a flame dried round bottomed flask under nitrogen atmosphere. To the resulting free floating powder, was added a solution of (2-azido-benzyl)-carbamic acid tert-butyl ester (250 mg, 1.0 mmol) in dry DMF (3 mL) dropwise at 0° C. under nitrogen atmosphere. The reaction mixture was stirred at this temperature for 30 min followed by dropwise addition of a solution of 1-(3-bromo-prop-1-ynyl)-4-fluoro-benzene (318.0 mg, 1.50 mmol) in dry DMF (1.5 mL). The reaction mixture was stirred at r.t. for 2 h. After the completion of the reaction as confirmed by TLC, the crude compound was extracted with ethylacetate (2×10 mL). The combined organic layer was washed with water (2×10 mL). Organic layer was separated, dried over Na2SO4 and concentrated in vacuo to afford the crude compound which was purified by column chromatography (silica gel, 1:9 EtOAc:Pet.Ether) to afford 3-(4-fluoro-phenyl)-4H,6H-1,2,5,10b-tetraaza-benzo[e]azulene-5-carboxylic acid tert-butyl ester (70 mg, 12.2%) as a viscous oil.

Provenance & Evidence