Trans-2,5-Dimethyl piperazine

C6H1206 L(-)-galactose 15572-79-9 20.90 1.5817 2 8919 C6H14N2 trans-2,5-dimethyl piperazine 2815-34-1 ... 

Abstract The conformationel properties of a series of asymmetric diamides and polyamides derived from cyclic r/- z s-l,2-dicarboxylic acid and either piperidine, piperazine, trans-2,5-dimethyl piperazine orA, A -dimethylethylendiamine have been extensively investigated with disparate techniques such as NMR spectroscopy, dipole moment measurements, hydrodynamic properties and empirical conformational energy calculations. 

Figure 3 Comparison of absorption and fluorescence (inset) spectra of different classes of C6oderivatives themethano-C6oderivative l -carboxy-l,2-methano[60]fullerene the pyrrolidino-C6o derivative N-ethyl-trans-2, 5 -dimethylpyrrolidino[3, 4 l,2][60] fullerene 33 (Fig. 24) (- - -),[B14al the C60 derivative 2-hydroxy-tetrahydrofu-ran[4, 5 l,2] [60]fullerene (—), and the amino-C60 derivative 3 (Fig. 4) AW -dimethyl-piperazine [2, 3 l,2][60]fullerene (-). (From Ref. 65.)...

Reactions of piperazine-2,5-diones with phosphorus pentachloride and phosphorus pentabromide have been described in Sections V.ID and V.IF, respectively. Aromatic aldehydes condense with 3-methylpiperazine-2,5-dione in the presence of acetic anhydride to form mainly mono-A -acetyl derivatives of trans-3-arylidene-6-methylpiperazine-2,5-diones (e.g., 96, R = Ac) (1066). In these products the acetyl group was shown to be attached to position 1 and the 4,5-amide group was found to be sterically hindered. Photolysis formed the cis isomers. Both isomers were deacetylated with methanolic potassium hydroxide (1066). Condensation of 1,4-diacetylpiperazine-2,5-diones with aldehydes has been applied to the synthesis of unsymmetrical 3,6-diarylidenepiperazine-2,5-diones and the reaction has been extended to l,4-diacetyl-3,6-dimethylpiperazine-2,5-diones (1624). Treatment of (96, R = H) with triethyloxonium tetrafluoroborate in dichloromethane gave the monoimino ether, 5-benzylidene-6-ethoxy-3-hydroxy-2-methyl-2,5-dihydropyrazine (97) (1066). l-Methylpiperazine-2,5-dione similarly treated gave 5-ethoxy-l-methyl-2-oxo-l,2,3,6-tetrahydropyrazine (which was condensed with anthranilic acid at 150° to 2-methyl-l,2-dihydropyrazino[2,l-fi]quinazoline-3(4/0.6-dione (98) (1625), and l,4-dimethylpiperazine-2,5-dione gave 5-ethoxy-l,4-dimethyl-2-oxo-1,2,3,4-tetrahydropyrazine and 5,5-diethoxy-l,4-dimethylpiperazin-2-one (1626). 

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