Ethyl isocyanate → 1-(5-Benzyloxy-7-bromo-benzothiazol-2-yl)-3-ethyl-urea

Participants

Reaction Conditions

Reaction Steps

To a suspension of vii (216 g, 0.64 mol) in 1,4-dioxane (4 L) was added ethylisocyanate (380 mL, 4.81 mol). The mixture was heated up to 80-85° C. overnight. The solvent was distilled off and the residue was co-evaporated with hexane. The residue was treated with H2O at 78-80° C. for 3-5 h. The resulting solid was filtered off and washed with hot H2O, dried under high vacuum to obtain viii (196 g, 75%). 1H-NMR (DMSO-d6, 400 MHz): δ 1.08 (t, J=7.20 Hz, 3H), 3.18 (q, J=6.80 Hz, 2H), 5.17 (s, 2H), 6.71 (br s, 1H), 7.15 (d, J=2.0 Hz, 1H), 7.26 (br s, 1H), 7.31-7.47 (m, 5H) and 10.82 (br s, 1H). MS: 405.90 [M+H]+.

Provenance & Evidence