Propylamine → HCID 22966909, compound

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Reaction Steps

In a sulfonation flask, 13.5 g (0.023 mol) of n-propylamine are added dropwise to 350 ml of tetrahydrofurane and 41.3 g (0.021 mol) of methyl 2-isothiocyanatothiophene-3-carboxylate, such that the internal temperature does not arise above 40° C. The reaction mixture is then stirred for 4 hours at reflux temperature and then the tetrahydrofurane is removed in a water-jet vacuum. The residue is taken up in ethyl acetate and extracted three times with water. The organic phase is then dried over sodium sulfate and the solvent is removed in the water-jet vacuum, giving the crude product, which is purified by column chromatography over silica gel (eluant: ethyl acetate/hexane=1:3). 32.4 g of methyl 2-(3-propylthioureido)-thiophene-3-carboxylate are obtained in the form of a beige powder having a melting point of 123-126° C.

Provenance & Evidence