Acetic Anhydride → HCID 69709047, compound

Participants

Reaction Steps

Anhydrous zinc chloride (7.0 g, 51.4 mmol) was fused with a nitrogen purge in a round bottom flask with an open flame. The reaction vessel was allowed to return to ambient temperature, then dioxane (100 mL) was added. To this mixture was added 2-methyl-3-(2-methylphenyl)-3H-thieno[3,2-d]pyrimidin-4-one (7.0 g, 27.34 mmol, preparation 2), acetic anhydride (7.7 mL, 82.0 mmol), and 2-fluorobenzaldehyde (8.6 mL, 10.2 mmol). The reaction was refluxed 14 hours, cooled to ambient temperature, and partitioned between ethyl acetate and water. The aqueous layer was extracted with ethyl acetate and the combined organic layer was filtered to obtain a small amount of product which had precipitated. The filtrate was washed with water and brine, dried over magnesium sulfate and concentrated to leave a mustard colored solid. This material was added to the product which had previously been collected and the combined material was flash chromatographed on silica gel (60×185 mm) eluting with 25-40% ethyl acetate/hexane to afford 5.06 g (51%) of 3-(2-methyl-phenyl)-2-[2-(2-fluoro-phenyl)-vinyl]-3H-thieno[3,2-d]pyrimidin-4-one as a light yellow solid.

Provenance & Evidence