Methanol → 6-Bromo-1,2,3,4-tetrahydroquinoxalin-2-one

温度

50 °C

5-bromo-2,3-diaminopyridine (2.0 g, 10.6 mmol) and glyoxylic acid monohydrate (1.23 g, 13.4 mmol) were combined in water (55 mL), sonicated for 10 minutes and stirred overnight. The product was filtered, washed with water (5×100 mL) and dried under vacuum to afford 2.214 g of crude product. To a suspension of this material in methanol (100 mL) was added NaBH4 (1.0 g, 26.3 mmol) with periodic cooling in an ice water bath to maintain reaction temperature below 35° C. After stirring for 4 hours, the reaction was quenched with 6N HCl (20 mL) and the resulting mixture stirred overnight. The mixture was warmed to 50° C. for 0.5 hour before removing volatile solvents by rotary evaporation. After adjusting the pH of the aqueous reside to 8 by the addition of 10N NaOH, the product was removed by filtration and washed with water (5×50 mL) to give the title compound (1.985 g, 82%). m.p. 265° C. (dec), 1H-NMR (DMSO-d6, 400 MHz) δ 10.47 (s, 1H), 7.65 (d, J=2.1 Hz, 1H), 7.01-6.99 (m, 2H), 3.94 (s, 2H).

1. customsonicated for 10 minutes
2. filtrationThe product was filtered
3. washwashed with water (5×100 mL)
4. customdried under vacuum
5. customto afford 2.214 g of crude product
6. temperaturewith periodic cooling in an ice water bath
7. temperatureto maintain
8. customreaction temperature below 35° C
9. stirringAfter stirring for 4 hours
10. customthe reaction was quenched with 6N HCl (20 mL)
11. stirringthe resulting mixture stirred overnight
12. custombefore removing volatile solvents
13. customby rotary evaporation
14. additionby the addition of 10N NaOH
15. customthe product was removed by filtration
16. washwashed with water (5×50 mL)

ORDレコード

ord-25c5b9f0038c4ac19269e76063ac50ed

出典データセット

uspto-grants-2009_10

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US07601716B2