Diethyl Malonate → Diethyl 3,3-dimethoxycyclobutane-1,1-dicarboxylate

HRID 546171노트

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HRID 546171 반응식
[C:1]([O:9][CH2:10][CH3:11])(=[O:8])[CH2:2][C:3]([O:5][CH2:6][CH3:7])=[O:4].[H-].[Na+].[H][H].Br[CH2:17][C:18]([O:23][CH3:24])([O:21][CH3:22])[CH2:19]Br.[Cl-].[NH4+]>CN(C)C=O>[CH2:10]([O:9][C:1]([C:2]1([C:3]([O:5][CH2:6][CH3:7])=[O:4])[CH2:19][C:18]([O:23][CH3:24])([O:21][CH3:22])[CH2:17]1)=[O:8])[CH3:11]

참가 물질

7

반응물 5

HCID 7761Diethyl MalonateHCID 24758Sodium hydrideHCID 25517Ammonium ChlorideHCID 27341961,3-Dibromo-2,2-dimethoxypropaneHCID 178418361HCID 178418361, 화합물

생성물 1

HCID 14143444Diethyl 3,3-dimethoxycyclobutane-1,1-dicarboxylate수율 25%

시약·촉매·용매 1

HCID 6228Dimethylformamide용매

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온도
135 °C

실험 절차

Diethyl malonate (14.3 ml, 94.20 mmol) was added to a stirred suspension of sodium hydride (4.75 g, 98.90 mmol, 50% dispersion in oil) in N,N-dimethylformamide (40 ml) at a rate such that the temperature was maintained below 40° C. On cessation of hydrogen evolution, the 1,3-dibromo-2,2-dimethoxy-propane (12.34 g, 47.09 mmol) was added in one portion and the reaction was heated at 135° C. for 48 h. To the cooled reaction was added an aqueous solution of ammonium chloride (100 g in 1.6 L) and extracted with hexane (4×50 ml). The combined extracts were then washed with water and aqueous saturated sodium bicarbonate solution, dried over magnesium sulfate and concentrated in vacuo. Unreacted 1,3-dibromo-2,2-dimethoxy-propane (6.9 g) was recovered by recrystallization from methanol. The filtrate was evaporated and more volatile fractions were removed by distillation under reduced pressure affording 3,3-dimethoxy-cyclobutane-1,1-dicarboxylic acid diethyl ester (3.05 g, 25%) as a light yellow oil: 1H NMR (300 MHz, CDCl3) δ ppm 1.26 (t, J=6.9 Hz, 6H, 2×CH3), 2.73 (s, 4H, 2×CH2), 3.15 (s, 6H, 2×OCH3), 4.22 (q, J=6.9 Hz, 4H, 2×OCH2).

후처리

  1. temperaturewas maintained below 40° C
  2. customTo the cooled reaction
  3. extractionextracted with hexane (4×50 ml)
  4. washThe combined extracts were then washed with water and aqueous saturated sodium bicarbonate solution
  5. dry with materialdried over magnesium sulfate
  6. concentrationconcentrated in vacuo
  7. customUnreacted 1,3-dibromo-2,2-dimethoxy-propane (6.9 g) was recovered by recrystallization from methanol
  8. customThe filtrate was evaporated
  9. custommore volatile fractions were removed by distillation under reduced pressure

출처 및 근거

ORD 기록
ord-805dc0d44f8a4e698e7265015351a4e4
출처 데이터셋
uspto-grants-2011_05
특허 번호
US07935699B2

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