Hydrochloric Acid → 5-Bromo-1-(2-hydroxyethyl)pyrazin-2(1H)-one

The crude 5-bromo-1-(2-(tert-butyldimethylsilyloxy)ethyl)pyrazin-2(1H)-one was dissolved in MeOH (30 mL) and concentrated HCl (0.15 mL) was added, and the reaction was stirred at room temperature. After 1 hour, the reaction was quenched with saturated sodium bicarbonate (3 mL) and then concentrated. The concentrate was treated with 5:1 CH2Cl2/MeOH and filtered. The filtrate was concentrated, and put on high vacuum in water bath (50° C.). This solid was washed with hexanes (50 mL) in portions, and then put on high vacuum again to afford the desired product (870.8 mg, 3.98 mmol, 90% purity, 52% yield over two steps). MS (ESI pos. ion) m/z (MH+): 219 (79Br), 221 (81Br). Calc'd exact mass for C18H13BrFN3O2: 218 (79Br), 220 (81Br). 1H NMR (400 MHz, CDCl3): 8.01 (s, 1H), 7.49 (s, 1H), 5.33 (br s, 1H), 4.08 (t, J=4.5 Hz, 2H), 3.96 (t, J=4.5 Hz, 2H).

1. customthe reaction was quenched with saturated sodium bicarbonate (3 mL)
2. concentrationconcentrated
3. additionThe concentrate was treated with 5:1 CH2Cl2/MeOH
4. filtrationfiltered
5. concentrationThe filtrate was concentrated
6. custom(50° C.)
7. washThis solid was washed with hexanes (50 mL) in portions

ORD-Eintrag

ord-e9100b2f8f644308a815c7152c360824

Quelldatensatz

uspto-grants-2012_11

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08314087B2