Aspinall, Samuel R. published the artcile< Synthesis of monoketopiperazines>, Safety of 3,3-Dimethylpiperazin-2-one, the main research area is .
ClCH2CO2Et (20.4 g.) in 100 cc. absolute EtOH, added slowly at room temperature to 60 g. (CH2NH2)2 in 300 cc. absolute EtOH (3 hrs.) and the mixture allowed to stand an addnl. 2 hrs., after which 11.3 g. EtONa in EtOH is added, the NaCl filtered, the solvent and excess (CH2NH2)2 removed by distillation and the residue heated at 200°/5 mm., give 45% of 2-ketopiperazine (I), b5 165°, m. 136° (m. ps. corrected); benzenesulfonamide, m. 188°. Similar yields were obtained at -15°, 0° and 80°. No I was formed when the reactants were used in the ratio of 1:1; with 1 mole (CH2NH2)2 and 1/8 mole of ClCH2CO2Et the yield is 25%; thus the reaction must be carried out under conditions which favor the formation of a monoalkyl derivative of the (CH2NH2)2. BrCH2CO2Et may be used but the yield is the same and the reaction has the disadvantage that the NaBr is soluble in the reaction mixture; if the EtOH is removed and EtONa in C6H6 is used, the NaBr may be separated, being insoluble in C6H6. Addnl. derivatives of I: picrate, m. 180°; HCl salt, m. 208°; phenylurea, m. 171°; phenylthiourea, m. 199°. Et α-bromobutyrate gives 60% of 3-ethyl-2-ketopiperazine, m. 60°; benzenesulfonamide, m. 148°; Et α-bromoisobutyrate gives 40% of 3,3-dimethyl-2-ketopiperazine, m. 134°; benzenesulfonamide, m. 206°.
Journal of the American Chemical Society published new progress about 22476-74-0. 22476-74-0 belongs to class piperazines, and the molecular formula is C6H12N2O, Safety of 3,3-Dimethylpiperazin-2-one.
Referemce:
Piperazine – Wikipedia,
Piperazines – an overview | ScienceDirect Topics