Reaktion #5446

Reaktionsgleichung

diisopropyl ethyl amine

Triethyl orthoformate

product

4-Bromo-7-methoxy-2,3-dihydro-1H-inden-1-one

BF3.Et2O

→

white solid

4-Bromo-7-methoxy-1-oxo-2,3-dihydro-1H-indene-2-carboxaldehyde diethy acetal

Lösungsmittel

methylene chloride

methylene chloride

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturcooled to -78° C
2. 2
   TemperaturThe reaction was then warmed to -15° C. for 2 h
3. 3
   Sonstigequenched in 5% NaHCO3 solution
4. 4
   Extraktionextracted with methylene chloride
5. 5
   WaschenThe organic extracts were washed with brine
6. 6
   Trocknendried (MgSO4)
7. 7
   Sonstigethe solvent removed
8. 8
   SonstigeThe crude product was triturated with cold hexane
9. 9
   Sonstigethe crystalline product collected

Vorschrift

Triethyl orthoformate (16.5 ml) was cooled to -30° C. and 15.0 ml BF3.Et2O in 50 ml methylene chloride was added. The reaction was warmed to 0° C. for 15 min, and then cooled to -78° C. To the reaction was added 12.05 g of the product from Example 34 in 50 ml methylene chloride, followed by dropwise addition of 19.4 ml diisopropyl ethyl amine. The reaction was then warmed to -15° C. for 2 h, then quenched in 5% NaHCO3 solution and extracted with methylene chloride. The organic extracts were washed with brine, dried (MgSO4), and the solvent removed. The crude product was triturated with cold hexane, and the crystalline product collected to yield 14.60 g of a white solid, mp: 76°-8° C. NMR (CDCl3) δ 1.05 (t, 3H), 1.27 (t, 3H), 3.03 (m, 2 H), 3.30 (m, 1H), 3.43-3.80 (m, 4H), 3.95 (s, 3H), 5.00 (d, 1H), 6.71 (d, 1H), 7.63 (d, 1H).

Quelle