Sodium hydride → HCID 18434021, compound

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Reaction Steps

In a sulfonation flask, 0.2 g (0.0049 mol) of a ca. 60% sodium hydride dispersion is added to 20 ml absolute tetrahydrofurane. Then 1.29 g (0.0047 mol) of methyl 2-(3-butylthioureido)thiophene-3-carboxylate, dissolved in 10 ml absolute tetrahydrofurane are added dropwise, such that the internal temperature remains constant at about 25° C. The mixture is stirred at reflux temperature for 3 hours and then the solvent is removed in a water-jet vacuum and the residue taken up in ethylacetate/water. After addition of acetic acid the mixture is extracted three times with ethylacetate and the organic phase dried over sodium sulfate. After removal of the solvent in a water-jet vacuum, 1.06 g of 3-butyl-2-thioxo-2,3-dihydro-1H-thieno[2.3-d]pyrimidin-4-one are obtained in the form of a brown powder having a melting point of 200-203° C.

Provenance & Evidence