Cesium carbonate → 6-Methoxy-8-(4-methyl-[1,4]diazepan-1-yl)-4-oxo-4H-chromene-2-carboxylic acid ethyl ester

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Into a 250 mL 3 neck round bottom flask equipped with a reflux condenser, nitrogen inlet and magnetic stirrer is placed 1.5 g (4.59 mmol, 1.0 equiv.) of 8-Bromo-6-methoxy-4-oxo-4H-chromene-2-carboxylic acid ethyl ester (Reference Example 2c), 84 mg (0.092 mmol, 0.02 equiv.) of tris dibenzylidineacetone dipalladium, 342 mg (0.55 mmol, 0.12 equiv.) of racemic 2,2′-bis(diphenylphosphino)-1,1′-binapthyl and 2 g of 4 A molecular sieves. To this suspension is added 150 mL of dry toluene. To the stirred suspension is then added 628 mg, 684 μL, (5.50 mmol, 1.2 equiv.) of 1-methylhomopiperazine, followed by 2.05 g (6.3 mmol, 1.4 equiv.) of cesium carbonate. The mixture is then heated to 80° C. for 3 days. At the end of this time completion was monitored by LC/MS analysis of an aliquot. When the reaction was determined to be complete it was cooled to room temperature then filtered through a plug of diatomaceous earth with toluene washing to remove solid by products. Purification by flash chromatography, using a gradient of 5 to 20% methanol in methylene chloride as eluent, yielded 1.0 g, (60%) of the desired product.

Herkunft & Nachweise