反応 #5874

反応方程式

potassium carbonate

potassium carbonate

N-cyano-N'-(2,2-dimethyl-4-chloroindan-1-yl)formamidine

methyl bromoacetate

→

1-(2,2-dimethyl-4-chloro-indan-1-yl)-5-imidazolecarboxylic acid methyl ester

収率 49.2%

溶媒

dimethylformamide

反応条件

後処理

1. 1
   その他After the exothermic reaction
2. 2
   workup.ADDITIONis added
3. 3
   ろ過The precipitate is filtered off from the hot solution
4. 4
   洗浄washed with 30 g of hot dimethylformamide
5. 5
   workup.ADDITIONThe combined filtrates are dropwise added at +60° C. to a solution of 14.2 g of tert. butylnitrite in 30 ml of dimethylformamide
6. 6
   その他rises to +67° C
7. 7
   workup.ADDITIONAfter 30 minutes the dropwise addition
8. 8
   温度The mixture is maintained at +70° to +75° C. for 2.5 hours
9. 9
   workup.ADDITIONpoured into ice-water
10. 10
    抽出extracted with ethyl acetate
11. 11
    洗浄The organic phase is washed with brine
12. 12
    乾燥dried with sodium sulfate
13. 13
    濃縮concentrated to dryness
14. 14
    その他The residue is purified by chromatography at a silica gel column with an ethyl acetate/hexane mixture (1:2 by volume)

実験手順

12.7 g of potassium carbonate are added to a solution of 21 g of N-cyano-N'-(2,2-dimethyl-4-chloroindan-1-yl)formamidine in 80 ml of dimethylformamide. 14.1 g of methyl bromoacetate are added dropwise. After the exothermic reaction has ceased the mixture is agitated for 1.5 hours at +50° C. another portion of 12.7 g of potassium carbonate is added and the mixture is stirred for 18 hours at +100° C. The precipitate is filtered off from the hot solution and washed with 30 g of hot dimethylformamide. The combined filtrates are dropwise added at +60° C. to a solution of 14.2 g of tert. butylnitrite in 30 ml of dimethylformamide. Immediate evolution of nitrogen is observed and the temperature of the mixture rises to +67° C. After 30 minutes the dropwise addition is completed. The mixture is maintained at +70° to +75° C. for 2.5 hours and then poured into ice-water and extracted with ethyl acetate. The organic phase is washed with brine, dried with sodium sulfate and concentrated to dryness. The residue is purified by chromatography at a silica gel column with an ethyl acetate/hexane mixture (1:2 by volume), affording 12.7 g of 1-(2,2-dimethyl-4-chloro-indan-1-yl)-5-imidazolecarboxylic acid methyl ester, having a melting point of 111°-113° C.

出典