1-methylpiperazin-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:

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

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

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

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

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

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: N,N-Diisopropylethylamine (11.5 ml) and 1-methyl-2-oxopiperazine (4.12 g) were added to a solution of 3,4-difluoronitrobenzene (1.82 ml) in acetonitrile (100 ml), and the mixture heated to reflux for 16 hours. Solvent was evaporated, and the residue chromatographed on silica, using as eluant a gradient increasing in polarity from 0 to 100% ethyl acetate in iso-hexane. Relevant fractions were combined and evaporated to give 3-fluoro-4-(4-methyl-3-oxopiperazin-1-yl)nitrobenzene (3.37 g). the mixture heated to reflux for 16 hours Solvent was evaporated the residue chromatographed on silica a gradient increasing in polarity from 0 to 100% ethyl acetate in iso-hexane evaporated

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

Procedure: 1-tert-Butoxycabonyl-4-methyl-3-oxopiperazine (3.87 g) was dissolved in trifluoroacetic acid (80 ml), and the mixture stirred at ambient temperature for 2 hours. Solvent was evaporated to give 1-methyl-2-oxopiperazine as a trifluoroacetate salt, with some excess trifluoroacetic acid. Solvent was evaporated