1-(2-piperazin-1-ylethyl)imidazolidin-2-one

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of piperazine (86 g, 1.0 mol), 1-(2-chloroethyl)-imidazolidin-2-one (74 g, 0.5 mol) and sodium carbonate (159 g, 1.5 mol) in ethanol (500 ml) was refluxed with stirring for 1.5 hours. A solution of 1-(2-chloroethyl)-imidazolidin-2-one (74 g, 0.5 mol) in methanol (75 ml) was then added in the course of 1.5 hours, at reflux temperature, whereupon the reaction mixture was refluxed for 18 hours. After cooling, the reaction mixture was filtered and evaporated in vacuo. The residue was dissolved in hot ethanol (100 ml), whereupon ethyl acetate (200 ml) was added. The crystals were filtered and dried to give 1-(2-(2-imidazolidinon-1-yl)ethyl)piperazine (60 g) mp. 136°-140° C. Additional 22 g could be obtained from the mother liquor. was refluxed at reflux temperature whereupon the reaction mixture was refluxed for 18 hours After cooling the reaction mixture was filtered evaporated in vacuo The residue was dissolved in hot ethanol (100 ml) whereupon ethyl acetate (200 ml) was added The crystals were filtered dried

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 35-1 (0.25 g, 1.06 mmol), 44-4 (0.21 g, 1.06 mmol) and DIEA (0.69 g, 5.32 mmol) were heated at 150° C. for 3 hours in n-butanol. Upon cooling the precipitate was filtered off, washed with n-butanol and ethyl ether and then dried to afford 44-5. Hi-Res MS: calc: 400.1663 found: 400.1633. 1H-NMR (CD3OD): 8.38(s, 1H); 7.99(s, 1H); 6.14(s, 1H); 3.65(m, 4H); 3.55(m, 2H); 3.39(m, 2H); 3.35(t, 2H); 2.59(complex, 6H). Upon cooling the precipitate was filtered off washed with n-butanol and ethyl ether dried to afford 44-5