Potassium Carbonate → 4-ethyl-8-methoxy-1H-pyrano[3,4-c]pyridine

HRID 357509노트

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HRID 357509 반응식
[CH:1](=[C:3]1[C:12]2[C:7](=[C:8]([O:13][CH3:14])[N:9]=[CH:10][CH:11]=2)[CH2:6][O:5][CH2:4]1)[CH3:2].C(=O)([O-])[O-].[K+].[K+]>C(O)CC.C1C=CC(P(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1.C1C=CC(P(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1.C1C=CC(P(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1.[Cl-].[Rh]>[CH2:1]([C:3]1[C:12]2[C:7](=[C:8]([O:13][CH3:14])[N:9]=[CH:10][CH:11]=2)[CH2:6][O:5][CH:4]=1)[CH3:2]

참가 물질

5

반응물 2

HCID 11430Potassium CarbonateHCID 540824384-ethylidene-8-methoxy-3,4-dihydro-1H-pyrano[3,4-c]pyridine

생성물 1

HCID 106315694-ethyl-8-methoxy-1H-pyrano[3,4-c]pyridine

시약·촉매·용매 2

HCID 84599Chlorotris(triphenylphosphine)rhodium(I)촉매3회HCID 10311-Propanol용매

실험 절차

A warmed solution of 4-ethylidene-8-methoxy-3,4-dihydro-1H-pyrano[3,4-c]pyridine, prepared as in example 3 (0.35 g, 1.83 mmol) in 30 mL of n-propanol is purged with a stream of nitrogen for 20 minutes prior to the addition of tris(triphenylphosphine)rhodium(I) chloride (0.025 g, 0.027 mmol). The reaction mixture is stirred at reflux for 15 hours under nitrogen and again treated with tris(triphenylphosphine)rhodium(I) chloride (0.025 g). After 2 hr, the flask is charged with potassium carbonate (0.50 g, 3.60 mmol), and heated for 2 hr. The mixture is then treated with tris(triphenylphosphine)rhodium(I) chloride (0.025 g). The mixture is heated to reflux for an additional 2 hr, filtered through Celite 545® and the filtrate is concentrated in vacuo. 1H NMR analysis shows an 1:8.3 ratio of exo-(4-ethylidene-8-methoxy-3,4-dihydro-1H-pyrano[3,4-c]pyridine) to endocyclic (4-ethyl-8-methoxy-1H-pyrano[3,4-c]pyridine) product. The dark residue is chromatographed on silica gel using 5% EtOAc/hexanes to provide 4-ethyl-8-methoxy-1H-pyrano[3,4-c]pyridine, the endocyclic form, as a colorless oil. 1H-NMR (CDCl3, 400 MHz): δ1.13 (t, J=7.4 Hz, 3H, --CH3); 2.30 (q, J=7.4 Hz, 2H, --CH2 --); 3.95 (s, 3H, --OCH3); 5.04 (s, 2H, --CH2O); 6.55 (d, J=5.4 Hz, 1H, Aromatic); 8.04 (d, J=5.4 Hz, Aromatic). Anal. Calcd for C11H13NO2.0.10CHCl3.0.05C3H8O: C, 65.54; H, 6.60; N,6.79. Found: C, 65.48; H, 6.57; N, 6.89. Mass Spectrum (FAB+): m/e 192 (M+1,100%).

후처리

  1. customis purged with a stream of nitrogen for 20 minutes
  2. temperatureat reflux for 15 hours under nitrogen
  3. temperatureheated for 2 hr
  4. temperatureThe mixture is heated
  5. temperatureto reflux for an additional 2 hr
  6. filtrationfiltered through Celite 545®
  7. concentrationthe filtrate is concentrated in vacuo
  8. customThe dark residue is chromatographed on silica gel using 5% EtOAc/hexanes

출처 및 근거

ORD 기록
ord-1a89a1959a974231a584a066c04391b9
출처 데이터셋
uspto-grants-1998_11
특허 번호
US05840898

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