Related Products of 6966-01-4,Some common heterocyclic compound, 6966-01-4, name is Methyl 3-amino-6-bromopyrazine-2-carboxylate, molecular formula is C6H6BrN3O2, 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.
Hydrazine hydrate (24 mL, 0.48 mol) was added dropwise to a stirred mixture of methyl 3-amino-6-bromopyrazine-2-carboxylate 29 (100 g, 0.42 mol) in EtOH (2 L). The mixture was heated at 50 C under nitrogen. The resulting thick suspension was stirred at 50 C for 16 h. Further hydrazine hydrate (2.5 mL) was added in one portion and the suspension was stirred at 50 C for a further 24 h. EtOH (500 mL) was charged to the thick reaction mixture and the mixture was allowed to cool to room temperature. The resulting suspension was filtered and the solid washed with ethanol (1 L) and dried in vacuo to give 3-amino-6-bromopyrazine-2-carbohydrazide (98 g, quantitative) as a cream solid. Pivalic anhydride (165 mL, 815 mmol) was added to a stirred mixture of 3-amino-6-bromopyrazine-2-carbohydrazide (172 g, 741 mmol) in acetonitrile (1.8 L) and the mixture was heated at 80 C for 1 h. The reaction was left to stir for 16 h. The required yellow solid material was isolated by filtration. The filtrate was partitioned between EtOAc (2 L) and aqueous sodium bicarbonate (2 L). The organic layer was washed with saturated brine and dried over MgSO4. The solution was filtered and concentrated to give an orange sticky solid which was triturated with MTBE (250 mL). The insoluble yellow solid was isolated by filtration. The combined solids were dried in vacuum at 50 C for 3 days to afford 3-amino-6-bromo-N’-pivaloylpyrazine-2-carbohydrazide (224 g, 96%) as a yellow solid. p-Toluenesulfonyl chloride (164 g, 862 mmol) was added portionwise to a suspension of 3-amino-6-bromo-N’-pivaloylpyrazine-2-carbohydrazide (227 g, 718 mmol) and DIPEA (300 mL, 1.8 mol) in acetonitrile (2.2 L). The mixture was stirred for 2 h at 70 C. The reaction was left to cool to room temperature overnight. The reaction mixture was partitioned between ethylacetate (2 L) and aq. sodium bicarbonate (2 L). The organic layer was washed with brine, dried with magnesium sulfate, filtered, and concentrated under reduced pressure. The resulting brown/beige solid was triturated with hot MTBE (1 L), isolated by filtration and dried to afford 5-bromo-3-(5-tert-butyl-1,3,4-oxadiazol-2-yl)pyrazin-2-amine 30 as a yellow solid (187 g, 87%). The mother liquors were evaporated to dryness. The crude solid was triturated with MTBE (500 mL), filtered and washed with 100 mL of MTBE. The resulting solid was air dried overnight to afford a second crop of 5-bromo-3-(5-tert-butyl-1,3,4-oxadiazol-2-yl)pyrazin-2-amine 30 (36 g, 17%).
These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route Methyl 3-amino-6-bromopyrazine-2-carboxylate, its application will become more common.
Reference:
Article; Barlaam, Bernard; Cosulich, Sabina; Delouvrie, Benedicte; Ellston, Rebecca; Fitzek, Martina; Germain, Herve; Green, Stephen; Hancox, Urs; Harris, Craig S.; Hudson, Kevin; Lambert-Van Der Brempt, Christine; Lebraud, Honorine; Magnien, Francoise; Lamorlette, Maryannick; Le Griffon, Antoine; Morgentin, Remy; Ouvry, Gilles; Page, Ken; Pasquet, Georges; Polanska, Urszula; Ruston, Linette; Saleh, Twana; Vautier, Michel; Ward, Lara; Bioorganic and Medicinal Chemistry Letters; vol. 25; 22; (2015); p. 5155 – 5162;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem