Tetrahydro-4H-pyran-4-one → 6'-(pyridin-4-yl)-2,3,5,6-tetrahydro-1'H-spiro [pyran-4,2'-thieno[3,2-d]pyrimidin]-4'(3'H)-one

Participants

Reaction Conditions

Reaction Steps

A mixture of 3-amino-5-(pyridin-4-yl)thiophene-2-carboxamide (0.078 g, 0.36 mmol), tetrahydro-4H-pyran-4-one (0.200 g, 2.00 mmol), p-toluenesulfonic acid monohydrate (0.076 g, 0.40 mmol) and toluene (3.0 mL) was stirred for 2 h at 90° C. The mixture was poured into aqueous sodium hydrogen carbonate (50 mL). Extraction with ethyl acetate/tetrahydrofuran (2:1, 2×30 mL), drying over magnesium sulfate, filtration and concentration at reduced pressure gave an oil. The oil was purified by column chromatography (12 g, silica, Combiflash, dichloromethane to 80:20 dichloromethane/methanol) to afford the title compound (0.050 g, 46%) as a yellow solid:

Provenance & Evidence