Application of 6270-63-9, A common heterocyclic compound, 6270-63-9, name is Pyrazin-2(1H)-one, molecular formula is C4H4N2O, 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.
A solution of compound pyrazin-2(1H)-one (11.0 g, 114 mmol), Mg(Ot-Bu)2 (39.0 g, 229 mmol) and t-BuOK (13.5 g, 120 mmol) in THF (220 mL) was stirred at 25 C. for 20 min under N2. And then compound (R)-2-bromo-4-methylpentanoic acid (33.5 g, 172 mmol) was added drop-wise into the mixture. The reaction was stirred at 25 C. for 20 hrs. HCl (3.0 M, 153 mL) was added dropwise to the mixture. The organic phase was washed with brine (100 mL), and concentrated. The mixture was purified by SFC (Instrument: Thar SFC80 preparative SFC; Column: Chiralpak AD-H 250*30 mm i.d. 5u; Mobile phase: A for CO2 and B for IPA (0.1% NH3H2O); Gradient: B %=35%; Flow rate: 75 g/min; Wavelength: 220 nm; Column temperature: 40 C.; System back pressure: 100 bar; Cycle time:13 min; Injection amount: 105 mg per injection) to give (S)-4-methyl-2-(2-oxopyrazin-1(2H)-yl)pentanoic acid (15.0 g, 61.7% Yield, 99.0% purity) as a yellow solid. 1H NMR (400 MHz, DMSO-d6) delta 7.96 (d, J=5.6 Hz, 1H), 7.58 (d, J=4.8 Hz, 1H), 7.30 (d, J=4.4 Hz, 1H), 5.14-5.21 (m, 1H), 1.84-1.92 (m, 2H), 1.17-1.26 (m, 1H), 0.82-0.84 (m, 6H).
The basis of chemical reaction formula synthesis, the synthesis route is composed of some specific reactions and combined according to certain logical thinking. We look forward to the emergence of more reaction modes in the future.