Hydrochloric Acid → ethyl 8-formyl-6-methyl-2-(trifluoromethyl)-2H-chromene-3-carboxylate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A mixture of 2-hydroxy-5-methyl-1,3-benzenedicarboxaldehyde (5.0 g, 30.46 mmole), K2CO3 (8.41 g, 60.92 mmole) and ethyl 4,4,4-trifluorocrotonate (7.68 g, 45.69 mmole) in anhydrous DMF (40.0 mL) was heated to 80° C. under a dry N2 atmosphere for 18 hrs. The mixture was then cooled, poured into 1.2 N HCl (100 mL) and extracted with EtOAc (2×100 mL). The combined extracts were washed with brine (100 mL), dried over MgSO4, filtered and concentrated in vacuo to give a dark red oil which was subject to flash chromatography (silica gel) and eluted with 50% CH2Cl2/hexane to give a light yellow solid (2.2 g, 23%): GCMS m/z 314.0 (M+). 1H NMR (CDCl3/400 MHz) 10.42 (s, 1H), 7.70 (s, 1H), 7.65 (s, 1H), 7.26 (s, 1H), 5.80 (q, 1H, J=7.0 Hz), 4.33 (m, 2H), 2.32 (s, 3H), 1.35 (m, 3H).

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