反応 #50213

反応方程式

5-(5-bromo-2-ethoxyphenyl)-1-methyl-3-n-propyl-1,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one

imidazole

potassium carbonate

iodine

→

title compound

収率 38.0%

5-[2-Ethoxy-5-(1-imidazolyl)phenyl]-1-methyl-3-n-propyl-1,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one

収率 38.0%

溶媒

water

dimethylformamide

反応条件

後処理

1. 1
   温度under reflux under nitrogen for 4.5 hours
2. 2
   温度cooled
3. 3
   抽出This mixture was extracted with a 9:1 mixture of dichloromethane and methanol (6×50 ml)
4. 4
   乾燥dried (MgSO4)
5. 5
   その他evaporated under vacuum
6. 6
   その他to give a pale brown oil
7. 7
   その他The oil was chromatographed on silica gel (20 g)
8. 8
   洗浄eluting with a mixture of dichloromethane, methanol and triethylamine (97.8:20:0.2)
9. 9
   その他to give
10. 10
    その他a yellow solid, crystallisation of which from ethyl acetate-hexane

実験手順

A solution of 5-(5-bromo-2-ethoxyphenyl)-1-methyl-3-n-propyl-1,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one (0.20 g, 0.0051 mol), imidazole (0.172 g, 0.0025 mol), anhydrous potassium carbonate (0.077 g, 0.00056 mol), copper bronze (0.036 g, 0.00057 mol) and iodine (0.015 g, 0.00012 mol) in dimethylformamide (10 ml) was heated under reflux under nitrogen for 4.5 hours, cooled and poured into water (50 ml). This mixture was extracted with a 9:1 mixture of dichloromethane and methanol (6×50 ml) and the extracts combined, dried (MgSO4) and evaporated under vacuum to give a pale brown oil. The oil was chromatographed on silica gel (20 g), eluting with a mixture of dichloromethane, methanol and triethylamine (97.8:20:0.2), to give a yellow solid, crystallisation of which from ethyl acetate-hexane gave the title compound as a cream solid (0.073 g, 38%), m.p. 193°-194° C. Found: C,63.61; H,5.97; N,22.03. C20H22N6O2 requires C,63.48; H,5.86; N,22.21%.

出典