反应详情

4-methylpiperazine-1-carbothiohydrazide (intermediate 6) can be formed according to the following scheme. Hydrazine hydrate (MW 50.06, 0.26 ml, 5.44 mmol, 1.1 eq) was added to a solution of imidazol-1-yl-(4-methyl-piperazin-1-yl)-methanethione (3; MW 210.30, 1.040 g, 4.95 mmol, 1 eq) in 30 ml ethanol at room temperature. The reaction mixture was stirred under reflux for 2 hours. This organic solution was concentrated. The solid thus obtained was triturated with diethyl ether and filtered to yield 4-methylpiperazine-1-carbothiohydrazide (6; MW 174.27, 0.53 g, 3.04 mmol, 61% yield) as a white solid which was used without further purification. TLC (CH2Cl2/MeOH: 90/10): Rf=0.15, Product UV and Ninhydrin stain active. 1H-NMR (400 MHz, DMSO-d6), δ ppm: 2.17 (s, 3H), 2.28 (t, 4H, J=5 Hz), 3.69 (t, 4H, J=5 Hz).

1. temperatureunder reflux for 2 hours
2. concentrationThis organic solution was concentrated
3. customThe solid thus obtained
4. customwas triturated with diethyl ether
5. filtrationfiltered