Acetic Anhydride → HCID 69710341, compound

Participants

Reaction Steps

To a mixture of fused zinc chloride (2.13 g, 15.6 mmol) and dioxane (75 mL), 2-methyl-3-(2-methylphenyl)-3H-thieno[3,2-d]pyrimidin-4-one (2.0 g, 7.81 mmol, preparation 2), and acetic anhydride (2.2 mL, 23.4 mmol) was added 2-pyridine carboxaldehyde (2.2 mL, 23.4 mmol). The reaction was refluxed 1.5 hours, cooled to ambient temperature, and diluted with aqueous sodium bicarbonate. The mixture was extracted with ethyl acetate and the organic extracts were washed with water and brine, dried over sodium sulfate and concentrated to leave a dark residue. This material was flash chromatographed on silica gel (45×125 mm). Elution with 20% ethyl acetate/hexane removed an unweighed impurity. Continued elution with 40% ethyl acetate/hexane gave a sticky yellow foam. The foam was triturated with 5% ethyl acetate/hexane to yield 1.9 g (70%) of 3-(2-methyl-phenyl)-2-[2-pyrid-2-yl-vinyl]-3H-thieno[3,2-d]pyrimidin-4-one as a yellow solid.

Provenance & Evidence