Triphenylphosphine → tert-butyl 4-{2-[3-(2-methylphenyl)-2,2-dioxido-2,1,3-benzothiadiazol-1(3H)-yl]ethyl}piperazine-1-carboxylate

Participants

Reaction Steps

In an analogous manner as general procedure II, step 1, a solution of 1-(2-methylphenyl)-1,3-dihydro-2,1,3-benzothiadiazole2,2-dioxide (0.2 g, 0.77 mmol) in tetrahydrofuran (10 mL) was cooled to 0° C., treated with triphenylphosphine (0.3 g, 1.2 mmol), tert-Butyl 4-(2-hydroxyethyl)piperazine-1-carboxylate (0.36 g, 1.54 mmol) were added followed by diisopropylazodicarboxylate (0.23 mL, 1.2 mmol to provide tert-butyl 4-{2-[3-(2-methylphenyl)-2,2-dioxido-2,1,3-benzothiadiazol-1(3H)-yl]ethyl}piperazine-1-carboxylate (0.25 g, 69%) as a white foam. HPLC purity 100.0% at 210-370 nm, 10.7 min.; Xterra RP18, 3.5 u, 150×4.6 mm column, 1.2 mL/min, 85/15-5/95 (Ammon. Form. Buff. Ph=3.5/ACN+MeOH) for 10 min, hold 4 min. HRMS: calcd for C24H32N4O4S+H+, 473.22170; found (ESI, [M+H]+Obs'd), 473.2229;

Provenance & Evidence