Yield:90000-71-8 51%

Reaction Conditions:

with water monomer;sodium hydroxide at 10; for 0.333333 h;

Steps:

Step-2: Synthesis of 5,6-dimethyl-3-oxo-3,4-dihydropyrazine-2-carboxamide (I-3)

To a stirred suspension of 2-aminomalonamide (I-2, 17.68 g, 151.16 mmol) and biacetyl (13 g, 151.16 mmol) in water (25 mL) was added aqueous NaOH (50% solution) (15 mL, 188.95 mmol) over a period of 20 min at 10 ^oC. After completion of addition, resulting reaction mixture was stirred for additional 2 h at the same temperature, pH of reaction mixture was adjusted to 6.0 (by acetic acid). The solid was precipitated out, was filtered and dried under vacuum to afford 5,6-dimethyl-3-oxo-3,4-dihydropyrazine-2-carboxamide (I-3, 13.00 g, yield: 51%) as a light yellow solid: ¹H NMR (400 MHz, DMSO- d₆) d 13.22 (s, 1H), 8.71 (s, 1H), 8.15 (s, 1H), 2.38 (s, 3H), 2.32 (s, 3H); ESI (m/z) 168 [C₇H₉N₃O₂ +H]⁺.

References:

WO2021/41970,2021,A1 Location in patent:Paragraph 0182; 0184