Ethyl 2-methylacetoacetate → 5,6-Dimethyl-2-thiouracil

Participants

Reaction Steps

To a stirred solution of potassium tert-butoxide (15.71 g, 0.140 mol) in tetrahydrofuran (200 mL) was added a solution of ethyl 2-methyl-3-oxobutanoate (20.0 g, 0.14 mol) and thiourea (10.55 g, 0.14 mol) in dry ethanol (150 mL). The resulting mixture was refluxed for 15 minutes and cooled down to ambient temperature. The formed precipitate was collected by filtration, washed with tetrahydrofuran (200 mL), and dissolved in water (200 mL). Acetic acid (100 mL) was added in to the resulting solution. The formed precipitate was collected by filtration and dried to yield 17 g (78.5%) of the titled compound. 1H NMR (300 MHz, DMSO-d6) δ ppm 1.74 (s, 3H) 2.09 (s, 3H) 12.19 (s, 1H).

Provenance & Evidence