Ethanesulfonamide → N-((5-bromopyridin-3-yl)(cyclopropyl)methyl)ethanesulfonamide

Participants

Reaction Conditions

Reaction Steps

A mixture of 5-bromonicotinaldehyde (372 mg, 2 mmol), ethanesulfonamide (273 mg, 2.500 mmol) and titanium(IV) isopropoxide (1172 μl, 4.00 mmol) in toluene (20 mL) was heated to reflux for 2 h. After concentration, the residue was dissolved in THF (25 mL) and cooled to −40° C. A solution of cyclopropylmagnesium bromide (10 mL, 5.00 mmol) was added dropwise and the resulting mixture was slowly warmed up to −20° C. and stirred at this temperature for 4 h. After quenching by saturated NH4Cl solution, filtration, extraction with CH2Cl2, the solution was dried over Na2SO4, and concentrated. The residue was purified by flash column (ethyl acetate/heptane, v/v, 10%-35%) and yielded the title product as oil (430 mg). 1H NMR (400 MHz, CDCl3): δ 0.2-0.3 (m, 1H), 0.4-0.5 (m, 1H), 0.5-0.6 (m, 1H), 0.6-0.7 (m, 1H), 1.0-1.1 (m, 1H), 1.1-1.2 (m, 3H), 2.55-2.75 (m, 2H), 3.6-3.7 (m, 1H), 4.51 (brd, J=4.8 Hz, 1H), 7.73 (s, 1H), 8.42 (s, 1H), 8.51 (s, 1H).

Provenance & Evidence