2423-65-6, These common heterocyclic compound, 2423-65-6, name is Pyrazine 1-oxide, its 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.
General Procedure 2:; Palladium-Catalyzed Direct Arylation with Aryl Chlorides and Bromides.; To a dried flask was added the diazine N-oxide (1.0 to 3.0 equiv.), K2CO3 (2.0 equiv.), Pd(OAc)2 (5 mol %) and HP(t-Bu)3BF4 (15 mol %). If the arylhalide is a solid, it is added at this point (1.0 equiv.). The flask and its contents were then purged under nitrogen for 10 minutes. If the aryl halide is a liquid, it is added via syringe after purging, followed by the addition of degassed dioxane (to produce a reaction concentration of 0.3 M relative to the halide). The reaction mixture was then heated at 110 C. until the reaction was complete, after which the volatiles were removed under reduced pressure and the residue was purified via silica gel column chromatography.2-Styrylpyrazine N-oxide (Table 4, Entry 12) Synthesised according to general procedure 2. Purification via silica gel column chromatography using 100% DCM, then a mixture of 10% Acetone/DCM gave a brownish solid, 32% yield with 2 eq. of the N-oxide and 40% yield with 3 eq. of the N-oxide). 1H NMR (300 MHz, CDCl3, 293K, TMS): delta 8.82 (1H, s), 8.31-8.22 (1H, m), 8.14-8.11 (1H, m), 7.72 (1H, d, J=16.5 Hz), 7.62 (2H, dd, J=3.0 and 7.8 Hz), 7.53 (1H, d, J=16.5 Hz), 7.45-7.34 (3H, m) 13C NMR (75 MHz, CDCl3, 293K, TMS): 145.8, 143.9, 136.7, 135.7, 133.9, 129.5, 128.9, 128.4, 127.5, 115.6.
Chemical properties determine the actual use. Each compound has specific chemical properties and uses. We look forward to more synthetic routes in the future to expand reaction routes of 2423-65-6.
Reference:
Patent; University of Ottawa; US2008/132698; (2008); A1;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem