tert-Butyl piperazine-1-carboxylate → Tert-butyl 4-(5-bromo-1,3-thiazol-2-yl)piperazine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

A solution of 2,5-dibromothiazole (1.00 g, 4.12 mmol) in DIPEA (3.00 mL) was charged with tert-butyl 1-piperazinecarboxylate (0.767 g, 4.12 mmol) and heated to 110° C. for 3 h and then an additional 16 h at rt. The reaction mixture was partitioned between CHCl3 and H2O, and the layers were separated. The aqueous layer was re-extracted with CHCl3 (3×) and the combined organic fractions were dried over Na2SO4, filtered and concentrated in vacuo. The crude material was purified by chromatography on silica gel [eluting with 0.5% EtOAc in CHCl3] resulting in the title compound as a light orange solid. 1H NMR (400 MHz, CDCl3): δ=1.47 (s, 9H), 3.37-3.44 (m, 4H), 3.51-3.59 (m, 4H), 7.08 (s, 1H). MS (ES+): m/z=348.09 (51/49) [MH+]. HPLC: tR=3.73 min (ZQ2, polar—5 min).

Provenance & Evidence