N,N'-Dimethylethylenediamine → 3-(2-Hydroxyethyl)-1,4-dimethyl-2-piperazinone

The mixture of sym. dimethylethylenediamine (1 eq, 53 g), bromobutyrolactone (1 eq, 100 g) and triethylamine (1 eq, 120 ml) in 1000 mL of tetrahydrofuran was refluxed overnight. The crude precipitate was filtered and thoroughly washed with diethyl ether. The ether was evaporated and the residue was purified by elution through a silica gel column using 2% (v/v) methanol in chloroform to obtain the title compound. A small sample was converted into a picrate and crystallized from methanol to obtain the picrate salt of the title compound: mp 157°-159° C.; IR (KBr) 3220, 1650, 1565 and 1330 cm-1 ; UV max (MeOH) 353 nm (ε 18090); and NMR (DMSO-d6) δ 2.1 (m, 2H), 2.9 and 2.93 (singlets, 6H), 3.5 (m, 6H), 3.95 (m, 1H), and 8.55 (s, 2H).