Ethanol → tert-butyl N-[4-[3-(2-amino-6-methyl-4-nitrophenyl)phenyl]sulfonyl-5-methylsulfanylthiophene-2-carboximidoyl]carbamate

Participants

Reaction Conditions

Reaction Steps

A flask with a stirbar was charged with {[4-(3-dihydroxyboranyl-benzenesulfonyl)-5-methylsulfanyl-thiophen-2-yl]-imino-methyl}-carbamic acid tert-butyl ester ((Example 140: step a (752 mg, 1.65 mmol), 2-bromo-3-methyl-5-nitro-phenylamine ((Example 295: step g) 306 mg, 1.32 mmol), aqueous Na2CO3 (2M, 4 mL, 8 mmol), ethanol (4 mL) and toluene (8 mL). The solution was sparged with argon for 10 min and Pd(PPh3)4 (294 mg, 0.25 mmol) was added. The biphasic solution was vigorously stirred under inert atmosphere at 80° C. for 16 h, then was cooled to rt. EtOAc (40 mL) and water (20 mL) were added and the layers were separated. The organic layer was washed with saturated NaHCO3 (2×20 mL), brine (20 mL) and was dried over sodium sulfate. Removal of the solvents in vacuo followed by column chromatography (10–40% EtOAc in hexanes) of the residue yielded the title compound (245 mg, 33%) as a yellow solid. 1H-NMR (CDCl3): δ 8.03 (ddd, 1H, J=1.2, 2.1, 8.1 Hz), 7.91 (s, 1H), 7.90 (t, 1H, J=1.6 Hz), 7.69 (t, 1H, J=7.9 Hz), 7.53 (app dd, 1H, J=0.7, 2.3 Hz), 7.50 (dt, 1H, J=1.4, 7.7 Hz), 7.44 (app dd, 1H, J=0.5, 2.3 Hz), 3.70 (s, 2H), 2.59 (s, 3H), 2.00 (s, 3H), 1.51 (s, 9H).

Provenance & Evidence