Oxalyl chloride → Methyl 1-(4-oxochroman-6-yl)cyclopropanecarboxylate

HRID 503287Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 503287
[CH3:1][O:2][C:3]([C:5]1([C:8]2[CH:13]=[CH:12][C:11]([O:14][CH2:15][CH2:16][C:17]([OH:19])=O)=[CH:10][CH:9]=2)[CH2:7][CH2:6]1)=[O:4].C(Cl)(=O)C(Cl)=O>C(Cl)Cl.CN(C=O)C>[O:19]=[C:17]1[C:10]2[C:11](=[CH:12][CH:13]=[C:8]([C:5]3([C:3]([OH:2])=[O:4])[CH2:6][CH2:7]3)[CH:9]=2)[O:14][CH2:15][CH2:16]1.[O:19]=[C:17]1[C:10]2[C:11](=[CH:12][CH:13]=[C:8]([C:5]3([C:3]([O:2][CH3:1])=[O:4])[CH2:6][CH2:7]3)[CH:9]=2)[O:14][CH2:15][CH2:16]1

Komponenten

6

Reaktionsbedingungen

Temperatur
2.5 °C

Versuchsvorschrift

To a solution of 1-[4-(2-carboxy-ethoxy)-phenyl]-cyclopropanecarboxylic methyl ester (5.0 g, 20 mmol) in CH2Cl2 (50 mL) were added oxalyl chloride (4.8 g, 38 mmol) and two drops of DMF at 0° C. The mixture was stirred at 0-5° C. for 1 h and then evaporated under vacuum. To the resulting mixture was added CH2Cl2 (50 mL) at 0° C. and stirring was continued at 0˜5° C. for 1 h. The reaction was slowly quenched with water and was extracted with EtOAc (50 mL×3). The combined organic extracts were dried over anhydrous Na2SO4 and evaporated under vacuum to give the crude product, which was purified by column chromatography on silica gel (petroleum ether/ethyl acetate 20:1-2:1) to give 1-(4-oxochroman-6-yl)cyclopropanecarboxylic acid (830 mg, 19%) and methyl 1-(4-oxochroman-6-yl)cyclopropanecarboxylate (1.8 g, 38%). 1-(4-Oxochroman-6-yl)cyclopropane-carboxylic acid: 1H NMR (400 MHz, DMSO) δ 12.33 (br s, 1H), 7.62 (d, J=2.0 Hz, 1H), 7.50 (dd, J=2.4, 8.4 Hz, 1H), 6.95 (d, J=8.4 Hz, 1H), 4.50 (t, J=6.4 Hz, 2H), 2.75 (t, J=6.4 Hz, 2H), 1.44-1.38 (m, 2H), 1.10-1.07 (m, 2H). MS (ESI) m/z (M+H+) 231.4. 1-(4-Oxochroman-6-yl)cyclopropanecarboxylate: 1H NMR (400 MHz, CDCl3) δ 7.83 (d, J=2.4 Hz, 1H), 7.48 (dd, J=2.4, 8.4 Hz, 1H), 6.93 (d, J=8.4 Hz, 1H), 4.55-4.52 (m, 2H), 3.62 (s, 3H), 2.80 (t, J=6.4 Hz, 2H), 1.62-1.56 (m, 2H), 1.18-1.15 (m, 2H).

Aufarbeitung

  1. customevaporated under vacuum
  2. additionTo the resulting mixture was added CH2Cl2 (50 mL) at 0° C.
  3. stirringstirring
  4. waitwas continued at 0˜5° C. for 1 h
  5. customThe reaction was slowly quenched with water
  6. extractionwas extracted with EtOAc (50 mL×3)
  7. dry with materialThe combined organic extracts were dried over anhydrous Na2SO4
  8. customevaporated under vacuum
  9. customto give the crude product, which
  10. customwas purified by column chromatography on silica gel (petroleum ether/ethyl acetate 20:1-2:1)

Quellen und Nachweise

ORD-Eintrag
ord-872764e1c49d430ab530416d70fa49e2
Quelldatensatz
uspto-grants-2010_08
Patentnummer
US07776905B2

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