Electric Literature of 18087-73-5,Some common heterocyclic compound, 18087-73-5, name is 3-Bromoimidazo[1,2-b]pyridazine, molecular formula is C6H4BrN3, traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route.
Unit Operation 1.1: 1 Sonogashira Reaction AP24595, palladium tetrakis triphenylphosphine (Pd(PPh3)4) , copper (I) iodide (Cul), triethylamine, and tetrahydrofuran (THF) are charged to the reactor. The mixture is stirred and degassed with nitrogen and then pre-degassed AP28141 is charged. The resulting mixture is brought to 45 – 55C and held for not less than 3 hours. The reaction completion is determined by IPC-1 (HPLC). If the IPC-1 criterion is met, the mixture is concentrated to a target volume and cooled. Unit Operation 1.2: Deprotection / 2nd Sonogashira Reaction AP25570, additional palladium tetrakis triphenylphosphine (Pd(PPh3)4), copper (I) iodide (Cul), and tetrahydrofuran (THF) are charged to the reactor. The mixture is concentrated and the water content is determined by IPC-2 (KF). If the IPC-2 criterion is met, the mixture is warmed to 45 – 60C and 25% sodium methoxide solution in methanol is slowly added. The reaction mixture is stirred and held for 30 – 60 minutes at 45 – 55C. The reaction progress is determined by IPC-3 (HPLC). The reaction mixture may be held at a lower temperature during the IPC analysis. If the IPC-3 criterion is met, the process is continued to Unit Operation 1.3. Unit Operation 1.3: Isolation of AP25047 HCI While stirring, the cool reaction mixture is quenched by addition of hydrogen chloride gas. A precipitate forms, and residual hydrogen chloride is removed from the suspension by a nitrogen purge. Tetrahydrofuran (THF) is replaced with toluene by an azeotropic distillation under reduced pressure. The resulting warm slurry is filtered in an agitated filter dryer and the filter cake is triturated and washed with warm toluene. The content of process impurity AP291 16 is determined by IPC-4 (HPLC). If the IPC-4 criterion is met, the wet filter cake is dried with agitation under a flow of nitrogen and reduced pressure at 35 – 45C (jacket temperature). The drying is monitored by IPC-5 (LOD, gravimetric). If the IPC-5 criterion is met, the crude AP25047 HCI is discharged and packaged in FEP bags in a plastic container. The isolated AP25047 HCI can be held for up to 7 days prior to forward processing. Unit Operation 1.4: Work-up The crude AP25047 HCI solid is charged to a reactor with dichloromethane (DCM) and washed with aqueous ammonia. The aqueous phase is back extracted with DCM for yield recovery purposes and the combined organic phase is washed a second time with aqueous ammonia. The organic layer is then washed with aqueous hydrochloric acid until the aqueous phase reaches a pH of 1-2, as indicated by IPC-6 (pH strips). If the IPC-6 criterion is met, the organic phase is treated with aqueous sodium bicarbonate until the aqueous wash reaches a pH of NLT 7, as indicated by IPC-7 (pH strips). The organic phase is briefly concentrated followed by the addition of fresh dichloromethane. The organic solution is passed through a silica gel pad, which is then rinsed with additional fresh dichloromethane for increased product recovery. Unit Operation 1.5: Crystallization of AP25047 The dichloromethane solution is concentrated under reduced pressure, and the dichloromethane is replaced with 2-propanol by azeotropic distillation under reduced pressure to the targeted final volume range. The resulting suspension is then cooled and further aged with agitation. Unit Operation 1.6: Isolation / Drying The precipitated product is isolated in an agitated filter dryer under a flow of nitrogen, and the filter cake is rinsed with 2-propanol. The wet filter cake is dried with agitation under a flow of nitrogen and reduced pressure at 45 – 55C (jacket temperature). The drying is monitored by IPC-8 (LOD, gravimetric). If the IPC-8 criterion is met, the product is sampled and packaged into polyethylene bags and placed within a heat sealed mylar coated aluminum foil bag, within an HDPE shipping container (Expected yield range, 65 – 89%).
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 3-Bromoimidazo[1,2-b]pyridazine, its application will become more common.
Reference:
Patent; ARIAD PHARMACEUTICALS, INC.; MURRAY, Christopher, K.; ROZAMUS, Leonard, W.; CHABER, John, J.; SHARMA, Pradeep; WO2014/93579; (2014); A2;,
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