1,4-Dioxane → tert-Butyl 5-(6-(3-(benzyloxy)phenylthio)-1,2,3,4-tetrahydronaphthalen-2-yl)-2,2-dimethyl-1,3-dioxan-5-ylcarbamate

Participants

Reaction Steps

Trifluoromethanesulfonic acid 6-(5-tert-butoxycarbonylamino-2,2-dimethyl-1,3-dioxinan-5-yl)-5,6,7,8-tetrahydro-naphthalen-2-yl ester (0.310 g, 0.000608 mol), 3-benzyloxy-benzenethiol (0.145 g, 0.000669 mol), tris(dibenzylideneacetone)-dipalladium(0) (0.0167 g, 0.0000182 mol) and xantphos (0.0211 g, 0.0000365 mol) were dissolved in 1,4-dioxane (10 mL, 0.1 mol). The solution was degassed by applying low vacuum and backfilling with N2 for 5 times. The pre-degassed N,N-diisopropylethylamine (0.350 mL, 0.00201 mol) in the same way was added. The mixture was heated to reflux under an atmosphere of nitrogen for 14 hours then cooled to r.t. tris(dibenzylideneacetone)dipalladium(0) (0.0501 g, 0.0000548 mol) and xantphos (0.0634 g, 0.000110 mol) was added. The mixture was degassed three times, heated to reflux for 6 more hours, cooled to r.t. The mixture was filtered, and concentrated to give a crude residue. Chromatography with EtOAc-hexane (0:100 to 20:80) two times gave a solid product (243 mg, 43%). 1H NMR (CHLOROFORM-d) δ: 7.31-7.44 (m, 5H), 7.18-7.23 (m, 1H), 7.17 (d, J=2.0 Hz, 2H), 7.04-7.09 (m, 1H), 6.97-7.04 (m, 1H), 6.84-6.92 (m, 1H), 6.79-6.84 (m, 1H), 5.02 (s, 2H), 4.86 (s, br, 1H), 3.95-4.05 (m, 4H), 2.77-2.97 (m, 4H), 2.64-2.76 (m, 1H), 2.47-2.60 (m, 1H), 2.00-2.14 (m, 1H), 1.51-1.60 (m, 6H), 1.41-1.51 (m, 9H). MS (M+Na+): 598.0.

Provenance & Evidence