反应详情

2.4 g (0.014 mol) of 1,4-dioxaspiro[4,4]nonan-7-carboxylic acid are dissolved in 56 ml of methylene chloride and after the addition of 2.2 g (0.014 mol) of carbonyldiimidazole stirred for 1 hour at ambient temperature. Then 3.2 g (0.014 mol) of 5,6-diamino-1,3-dipropyluracil are added and the mixture is stirred for a further 4 hours at ambient temperature. The solution is evaporated down in vacuo, the oily residue is mixed with 70 ml of water and 4.5 g of Ca(OH)2 and stirred for 1 hour at 70° C. 100 ml of 50% NaOH are added, the mixture is stirred for a further hour at 70° C. and for 16 hours at ambient temperature. Whilst being cooled with ice, the solution is adjusted to pH 6 with HCl and extracted with methylene chloride. After drying and evaporation in vacuo the combined organic phases yield a crystalline residue which is recrystallised from ethanol using activated charcoal. 0.8 g (16%) of white crystals are obtained, m.p. 147°-148° C.

1. stirringthe mixture is stirred for a further 4 hours at ambient temperature
2. customThe solution is evaporated down in vacuo
3. additionthe oily residue is mixed with 70 ml of water and 4.5 g of Ca(OH)2
4. stirringstirred for 1 hour at 70° C
5. addition100 ml of 50% NaOH are added
6. stirringthe mixture is stirred for a further hour at 70° C. and for 16 hours at ambient temperature
7. temperatureWhilst being cooled with ice
8. extractionextracted with methylene chloride
9. customAfter drying
10. customevaporation in vacuo the combined organic phases
11. customyield a crystalline residue which
12. customis recrystallised from ethanol using activated charcoal