Hydrazinium chloride → 2-methylsulfanyl-4-(1H-pyrazol-5-yl)pyrimidine

Participants

Reaction Steps

A solution of (2E)-3-(dimethylamino)-1-[2-(methylthio)pyrimidin-4-yl]prop-2-en-1-one (1-4, 1.0 g, 4.48 mmol, 1 equiv) and hydrazine hydrochloride (0.62 g, 8.96 mmol, 2 equiv) in ethanol(20 mL) was heated at reflux for 20 hours. The reaction mixture was concentrated and the residue was partitioned between ethyl acetate(2×50 mL) and sat. sodium bicarbonate solution. The combined organic extracts were dried over magnesium sulfate and concentrated to a solid which was triturated with ether to provide 2-(methylthio)-4-(1H-pyrazol-5-yl)pyrimidine (4-1) as a tan solid. 1H NMR (500 MHz, CDCl3) δ 10.8 (br s, 1H), 8.55 (d, 1H, J=5 Hz), 7.68 (d, 1H, J=5 Hz), 7.40 (br s, 1H), 6.96 (br s, 1H), 2.63 (s, 3H).

Provenance & Evidence