反应详情

温度

22 °C

A biphasic solvent mixture of 1100 mL (22 volumes) tetrahydrofuran and 550 mL (11 volumes) of aqueous sodium carbonate solution was stirred at 22° C. in a 3000 mL three-necked round-bottomed flask. To this, 2-amino-6-chloro-5-nitro-4-pyrimidinol (11) was added portionwise. The resulting yellow solution was treated with a solution of 5-methylfuran-2-boronic acid in ca. 30 mL THF (0.43 mol, 2 eq 2-methylfuran initially). Tetrakis(triphenylphosphine)palladium (0) (5%, 0.0072 moles, 8.32 g) was added and the reaction mixture heated to a temperature of 70° C. for 3 hr. The reaction mixture was cooled to 22° C. A small amount of turbidity was apparent at this point. The entire mixture was filtered and the filtrate reduced in vacuo to remove the tetrahydrofuran phase, leaving behind the alkaline aqueous phase. 1000 mL (20 volumes) ethyl acetate was added and the mixture stirred vigorously for 15 min (this step serves to wash out neutral contaminants, particularly triphenylphosphine oxide). The aqueous and organic phases were separated and the organic phase back-extracted with aqueous sodium carbonate (800 mL). The combined aqueous phase was cooled using an ice-bath and acidified (through drop-wise addition of HCl) to pH 7. The resulting bright yellow precipitate was filtered under vacuum, washed with water and dried at 40° C. This method gave 37.8 g (67. %) of the required product.

1. temperaturethe reaction mixture heated to a temperature of 70° C. for 3 hr
2. temperatureThe reaction mixture was cooled to 22° C
3. filtrationThe entire mixture was filtered
4. customto remove the tetrahydrofuran phase
5. customleaving behind the alkaline aqueous phase
6. stirringthe mixture stirred vigorously for 15 min (this step
7. washto wash out neutral contaminants, particularly triphenylphosphine oxide)
8. customThe aqueous and organic phases were separated
9. extractionthe organic phase back-extracted with aqueous sodium carbonate (800 mL)
10. temperatureThe combined aqueous phase was cooled
11. addition(through drop-wise addition of HCl) to pH 7
12. filtrationThe resulting bright yellow precipitate was filtered under vacuum
13. washwashed with water
14. customdried at 40° C