Dimethylformamide → 2,3-Dihydrobenzofuran-6-carbaldehyde
Reaktionsgleichung
Br[C:2]1[CH:10]=[CH:9][C:5]2[CH2:6][CH2:7][O:8][C:4]=2[CH:3]=1.C([Li])CCC.CN([CH:19]=[O:20])C>C1COCC1.CCCCCC>[O:8]1[C:4]2[CH:3]=[C:2]([CH:19]=[O:20])[CH:10]=[CH:9][C:5]=2[CH2:6][CH2:7]1Komponenten
Edukt 3
Produkt 1
Reagenzien, Katalysatoren, Lösungsmittel 2
Reaktionsbedingungen
- Temperatur
- -78 °C
Versuchsvorschrift
To an cooled solution (−78° C. internal temp) of 1 g of 6-bromo-2,3-dihydro-1-benzofuran (prepared as described by Z. J. Song, M. Zhao, L. Frey, J. Li, L. Tan, C. Y. Chen, D. M. Tschaen, R. Tillyer, E. J. J. Grabowski, R. Volante, P. J. Reider, Y. Kato, S. Okada, T. Nemoto, H. Sato, A. Akao, T. Mase, Organic Letters, 2001, Vol. 3, No. 21, 3357-3360) in 20 mL of anhydrous THF was added 4 mL of 2.5 M n-butyllithium in hexane. After stirring 10 min at −78° C., 0.5 mL of anhydrous DMF was added and the mixture allowed to warm to −20° C., quenched with 20 mL of 3N HCl and extracted into 2×50 mL of ether. Combined extracts dried over MgSO4 and concentrated under reduced pressure. Purification by flash chromatography (0-20% ethyl acetate in hexanes) gave the product as white crystalline solid. MS (m+1)=149.1; 1H NMR (400 MHz, CDCl3) 9.9 (s, 1H), 7.4 (m, 2H), 7.3 (s, 1H), 4.62 (t, 2H), 3.28 (t, 4H).
Aufarbeitung
- temperatureto warm to −20° C.
- customquenched with 20 mL of 3N HCl
- extractionextracted into 2×50 mL of ether
- dry with materialCombined extracts dried over MgSO4
- concentrationconcentrated under reduced pressure
- customPurification by flash chromatography (0-20% ethyl acetate in hexanes)
Quellen und Nachweise
- ORD-Eintrag
- ord-843e3c2b701949c494ffab7051276bc8
- Quelldatensatz
- uspto-grants-2010_12
- Patentnummer
- US07855201B2
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