Cesium fluoride → 1,3-Dimethyl-5-(2-propen-1-yl)-2,4(1H,3H)-quinazolinedione

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of Step 4 intermediate (40 g, 126 mmol) in 1,4-dioxane (1.3 lit) was added cesium fluoride (38.3 g, 252 mmol) and allylboronic acid pinacol ester (42.5 ml, 225 mmol) under nitrogen atmosphere and the mixture was degassed for 10 min. Tetrakis(triphenylphosphine)palladium(0) (14.46 g, 12 mmol) catalyst was added and the mixture was stirred at 100° C. for 20 h under nitrogen atmosphere. The mixture was diluted with water (500 ml) and extracted with ethyl acetate (3×500 ml). The combined extracts were concentrated and the residue obtained was purified by silica gel column chromatography to give 26.5 g of the product as an off-white solid; 1H NMR (δ ppm, CDCl3, 300 MHz): 7.54 (t, J=7.8, 1H); 7.08 (t, J=6.9, 2H); 6.18-6.00 (m, 1H); 5.06-4.95 (m, 2H); 4.04 (d, J=6.3, 2H); 3.60 (s, 3H); 3.45 (s, 3H). MS (m/z): 231.37 ([M+H]+).

Provenance & Evidence