tert-Butyl (2S)-2-(2-methylpropyl)piperazine-1-carboxylate → tert-butyl (2S)-2-isobutyl-4-[2-(1-tritylpyrazolo[5,4-b]pyridin-3-yl)thiazol-4-yl]piperazine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

3-(4-bromothiazol-2-yl)-1-trityl-pyrazolo[5,4-b]pyridine (234 mg, 0.4470 mmol), sodium tert-butoxide (60.14 mg, 0.6258 mmol), tert-butyl (2S)-2-isobutylpiperazine-1-carboxylate (130.0 mg, 0.5364 mmol), Pd2 dba3 (4.093 mg, 0.004470 mmol) and RUPHOS (8.343 mg, 0.01788 mmol) in toluene (3 mL) were heated in microwave for 2 h at 100° C. Added more Pd2 dba3 (4.093 mg, 0.004470 mmol) and RUPHOS (8.343 mg, 0.01788 mmol) and heated at 100° C. for a further 1 h in microwave. Cooled to room temperature, diluted with EtOAc, washed with water, brine, dried (MgSO4), filtered and concentrated in vacuo. Crude product purified by flash chromatography (12 g SiO2, 0 to 15% EtOAc/petrol) to leave product as a luminous green sticky oil (149 mg, 49%); 1H NMR DMSO-d6 δ 1.01 (dd, 6H), 1.53 (s, 9H), 1.69-1.57 (m, 2H), 1.81-1.76 (m, 1H), 2.80 (td, 1H), 2.94 (dd, 1H), 3.28 (t, 1H), 3.81 (d, 1H), 3.90 (d, 1H), 4.09 (br s, 1H), 4.37 (br s, 1H), 7.15 (dd, 1H), 7.28 (s, 16H), 8.29 (dd, 1H), 8.70 (dd, 1H); ES+ 685.47.

Provenance & Evidence