Dimethylformamide → N-tert-Butyl-3-(diazenylmethyl)-4,5,6,7-tetrahydrobenzo[b]thiophene-2-carboxamide

Participants

Reaction Conditions

Reaction Steps

To a solution of 117a (100 g, 0.42 mol, 1.0 equiv) in THF (500 mL) was slowly added n-BuLi (672 mL, 2.5M in THF, 1.68 mol, 4.0 equiv) at −78° C. under argon. The mixture was stirred for 2 h. DMF (306 g, 4.2 mol, 10.0 equiv) was added to the mixture while the temperature was maintained at −78° C. After another 2.0 h, the reaction was quenched with methanol (500 mL) at −78° C. It was stirred for 0.50 h at room temperature. 80% aqueous hydrate hydrazine (131 g, 2.1 mol) was added and the mixture was refluxed at 65° C. overnight. The organic solvent was removed under reduced pressure. The residue was filtered and the yellow solid collected was washed with water. The solid was dried in vacuo to afford crude 117b, which was used in the next step without further purification. MS: [M+H]+ 280.

Provenance & Evidence