Chlorotrimethylsilane → 1-(1,5-dimethyl-1H-pyrazol-3-yl)ethanone

HRID 1825332

반응식

HRID 1825332 반응식
[CH3:1][N:2]1[C:6]([CH3:7])=[CH:5][C:4]([C:8]([O:10]CC)=O)=[N:3]1.[CH3:13][Si](Cl)(C)C.C[Li]>O1CCCC1>[C:8]([C:4]1[CH:5]=[C:6]([CH3:7])[N:2]([CH3:1])[N:3]=1)(=[O:10])[CH3:13]

참가 물질

5

반응물 3

HCID 6397ChlorotrimethylsilaneHCID 1385771,5-Dimethyl-3-ethoxycarbonylpyrazoleHCID 178418348HCID 178418348, 화합물

생성물 1

HCID 131074871-(1,5-dimethyl-1H-pyrazol-3-yl)ethanone

시약·촉매·용매 1

HCID 8028Tetrahydrofuran용매

반응 조건

온도
-100 °C

실험 절차

Ethyl 1,5-dimethylpyrazole-3-carboxylate (3.59 g, 21.4 mM) was dissolved in dry tetrahydrofuran (70 ml) and cooled to −100° C. whilst under an atmosphere of argon. Trimethylsilylchloride (13.5 ml, 107 mM) was added by rapid dropwise addition. Immediately after methyllithium (77.7 ml of 1.1M solution in diethylether, 85.5 mM) was added dropwise in such a way that the internal temperature never exceeded −85° C. After complete addition the heterogeneous reaction was allowed to warm to room temperature. Most of the solvent was removed by evaporation in vacuo before treating with ethanol (6 ml) followed by water (6 ml). After vigorously stirring for 5 minutes the mixture was diluted with ethyl acetate and water. The pH was adjusted to 7 by treating with saturated sodium bicarbonate solution. The organic phase was separated and washed with brine before drying (MgSO4). Purification was accomplished by chromatography on silica gel (12×4.25 cm) loading in dichloromethane and eluting with 40% ethylacetate in hexane followed by 60% ethyl acetate in hexane. Removal of the solvents gave the title compound as a coloured oil which solidified on standing at room temperature (1.42 g): υmax (CH2Cl2) 1679, 1551, 1448, and 1373 cm−1; δH (CDCl3) 2.30 (3H, s), 2.54 (3H, s), 3.84 (3H, s), 6.53 (1H, d, J 0.55 Hz); E.I. m/e 138 (95%), NH3DCI m/e 139 (100%).

후처리

  1. additionAfter complete addition
  2. customthe heterogeneous reaction
  3. temperatureto warm to room temperature
  4. customMost of the solvent was removed by evaporation in vacuo
  5. additionbefore treating with ethanol (6 ml)
  6. additionwas diluted with ethyl acetate and water
  7. additionby treating with saturated sodium bicarbonate solution
  8. customThe organic phase was separated
  9. washwashed with brine
  10. dry with materialbefore drying (MgSO4)
  11. customPurification
  12. washeluting with 40% ethylacetate in hexane
  13. customRemoval of the solvents

출처 및 근거

ORD 기록
ord-1bc518db245f44e29d73d14b4c085b69
출처 데이터셋
uspto-grants-2006_05
특허 번호
US07045619B2

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