Piperazine → HCID 71668917, compound

Participants

Reaction Conditions

Reaction Steps

An intimate mixture of 6-chloro-imidazo[1,2-b]pyridazine [6775-88-6] (4.1 g, 26.5 mmol and piperazine [110-85-0] (11.4 g, 132.8 mmol) was heated to 120° C. and stirred as a melt under N2 blanket for 2 h. The cooled reaction was partitioned between water and ethyl acetate, the extract dried (MgSO4), and evaporated to yield 5.6 g of 6-piperazin-1-yl-imidazo[1,2-b]pyridazine which, without purification, was suspended in ethyl acetate (250 mL). To this stirred mixture was added Hunig's base [7087-68-5] (9.6 mL, 55.1 mmol) and di-tert-butyl pyrocarbonate [24424-99-5] (7.2 g, 33.2 mmol). The N2 blanketed mixture was stirred overnight at ambient temperature then partitioned between brine and ethyl acetate. The phase separated extract was dried (CaSO4), evaporated, and crystallized from ethyl acetate/heptane to provide a white crystalline powder, mp. 122-123° C. 1H NMR (400 MHz, DMSO-d6) δ ppm 1.43 (s, 9H) 3.46 (s, 8H) 7.16 (d, J=10.11 Hz, 1H) 7.50 (s, 1H) 7.81-7.94 (m, 2H). 13C NMR (100 MHz, DMSO-d6) δ ppm 28.03, 42.66, 45.42, 79.07, 110.58, 116.43, 125.91, 131.62, 135.77, 153.88, 154.71. LRMS (ESI) m/z 304.2 [(M+H)]+, calc'd for C15H21N5O2: 303.37.

Provenance & Evidence