Sulfuric acid magnesium salt (1:1) → HCID 23433661, compound

Participants

Reaction Steps

To an oven-dried 1 L r.b. flask containing 3-tert-butyloxycarbamoylaniline (17.4 g, 83.5 mmol), MgSO4 (50 g, 5 equivuiv), and 4-tert-butylcatechol (420 mg, 3 mol %) in 120 mL acetone (approx 0.75 M in the aniline) was added iodine (1.07 g, 5 mol %), and the mixture was heated to reflux for 8 h. The crude reaction mixture was then cooled to rt, filtered through a bed of Celite™ on a fritted-glass funnel, rinsing with ethyl acetate, dried (Na2SO4), and concentrated under reduced pressure. Purification by flash column chromatography (silica gel, hexanes/ethyl acetate, gradient elution) afforded 19.9 g (82%) of 7-tert-butyloxycarbamoyl-1,2-dihydro-2,2,4-trimethylquinoline as a white solid, which was further purified by recrystallization from acetonitrile to give white needles. Data for 7-tert-butyloxycarbamoyl-1,2-dihydro-2,2,4-trimethylquinoline: 1H NMR (400 MHz, CDCl3) 6.93 (d, J=8.3, 1H, 5-H), 6.81 (br s, 1H, HNBoc), 6.34 (m, 2H, 6,8-H), 5.21 (d, J=0.9, 1H, 3-H), 3.71 (br s, 1H, NH), 1.94 (d, J=1.0, 3H, 4-CH3), 1.50 [s, 9H, (CH3)3CO)], 1.24 [s, 6H, 2-CH3)2].

Provenance & Evidence