Dimethylformamide → HCID 13393803, compound

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Reaction Steps

As in example 1, but using 2.2 g flavan-3-one, 12 ml dimethylformamide and 3 ml phosphorous oxychloride. Reaction time is one hour at 0°-5°. After hydrolysis and usual work up the residual oil is purified by column chromatography. The best fractions give a pale yellow oil of pure 3-chloro-4-formyl-flav-3-ene. TLC (n-hexane/acetone 4:1, SiO2) single spot, Rf =0.47. NMR (90 MHz, CDCl3):δ(ppm)=5.86 [1H, s, H-C(2)]; 6.7-7.5 [3H, m, H-C (6,7,8)]; 7.35 [5H, S,C6H5 ]; 8.15 [1H, dd, H-C(5)].

Provenance & Evidence