Piperazine 2.5- dioxo

Piperazine, I -diethyIcarbamyI-4-methyl-metabolism, 1, 227 Piperazine, N,JV-dimethyI-epoxy resin curative. 1, 406 Piperazine, 2,5-dioxo-occurrence, 3, 187 Piperazine-2,5-dione polymers, 1, 298... [Pg.746]

Piperazin 2,5-Dioxo-l-hydroxy-E16a, 190 (OR-OH) Propansaure 2-Methyl-2-nitrato- -nitril XI/2, 115... [Pg.155]

Piperazin 2,5-Dioxo-3-isopropyl-[Cyclo-(L-Val-Gly)] E21f. 5832 (H2N - CH2 - COOR + 4-R-2,5-dioxo-l,3-oxazolidin)... [Pg.403]

Piperazin 2,5-Dioxo-l-hydroxyl-isopropyl- E16a, 190 (O —R-Spalt.)... [Pg.403]

To this acid was then added 1 g of 4-ethyl-2,3-dioxo-1-piperazinocarbonyl chloride (from the reaction of N-ethylethylenediamine and diethyl oxalate to give 2,3-dioxo-4-ethyl-piperazine which Is then reacted with phosgene) and the resulting mixture was reacted at 15°C to 20°C for 2 hours. After the reaction, a deposited triethylamine hydrochloride was separated by filtration, and the filtrate was incorporated with 0.4 g of n-butanol to deposit crystals. The deposited crystals were collected by filtration to obtain 1.25 g of white crystals of 6-[ D(—l-Ct-(4-ethyl-2,3-dioxo-1 -piperazinocarbonylaminolphenylacetamido] penicillanic acid. Into a solution of these crystals in 30 ml of tetrahydrofuran was dropped a solution of 0.38 g of a sodium salt of 2-ethyl-hexanoic acid in 10 ml of tetrahydrofuran, upon which white crystals were deposited. The deposited crystals were collected by filtration, sufficiently washed with tetrahydrofuran and then dried to obtain 1.25 g of sodium salt of 6-[D(—)-a-(4-ethyl-2,3-di-0X0-1-piperazinocarbonylaminolphenylacetamido] penicillanic acid, melting point 183°C to 185°C (decomposition), yield 90%. [Pg.1245]

Dioxo-piperazine ergeben in THF erst nach einer RiickfluBdauer von 165 Stdn., also nach einer Woche, die besten Ausbeuten an Piperazincns . Cyclischc Oligamidc werden meist nur langsam reduziert1". [Pg.248]

Dioxo-piperazine werden analog den anderen Amiden mit guter Ausbeute zu Pipe-razinen reduziert (Katholyt Eisessig mit 25% halbkonz. Schwefelsaure, Blei-Elektroden Ausbeuten —70% d.Th.)10 ... [Pg.602]

RN 18833-13-1 MF C H,oN404 XC4H10N2 MW unspecified EINECS 242-614-3 CN l,2,3,6-tetrahydro-l,3-dimethyl-2,6-dioxo-7//-purine-7-acetic acid compd. with piperazine... [Pg.10]

Benzyl-5-(1-benzyl-1 H-imidazol-4-ylmethyl)-3,6-dioxo-piperazine-2-carboxylic Acid Cyclohexylamide (109). For major diastereomer 1H NMR (500 MHz, CD3OD, ppm) 8.91 (s, 1H), 7.32-7.44, 7.23-7.32,... [Pg.493]

Bulk GC Silyation USP-G2 (200°C) FID USP 23, for determination 5-benzyl-3,6-dioxo 2-piperazine-acetic acid HPLC [51,200-202,1124, 1144-1146] PI... [Pg.152]

The content of the principal degradation impurity, 3-methylenecarboxyl-6-benzyl-2,5-diketopiperazine (also called 5-benzyl-3,6-dioxo-2-piperazine-acetic acid), is controlled at not more than 1.5% [19, 20]. Other controlled impurities are moisture (i.e., loss on drying, < 4.5%), residue on ignition (< 0.2%), arsenic (< 3 ppm), heavy metals (< 0.001%), and related substances (< 2%) [19]. [Pg.14]

Piperazin 4-(Carboxy-methyl)-2,5-dioxo-1-hydroxy- Elba, 190 (O — R-Spalt.)... [Pg.280]

Piperazin 5,5-Dimethyl-2,3-dioxo-l-isopropyl- XI/2, 21 Propen l-Cyclohexylamino-2-nitro-E15/2, 1373 (Imin + R-O-N02)... [Pg.662]

IJC468, 78IJC(B)ioi5). Treatment of the piperazine ester (482) with phenyl isocyanate followed by refluxing hydrochloric acid gave the dioxo derivative (483) (62HCA2383). [Pg.645]

Analogously, 2,5-dioxo-8-ethyl-l,2,5,8-tetrahydropyrido[2,3-i/]pyrimi-dine-6-carboxylic acid is silylated-aminated with piperazine, HMDS, and... [Pg.158]

Scheme 164 Phosgenation of dioxo piperazine and structure of the derived antibiotic Piperacillin,...

The steps of prenylation and dehydrogenation which follow (94) in the biosynthesis of these neoechinulins is unknown but from knowledge of echinulin biosynthesis (Scheme 6) introduction of the side chain at C-2 may be the next step. Prenylation of the benzene unit seems, by inspection of structures (97) through (101), to depend on C-8—C-9 unsaturation rather than the structure of the dioxo-piperazine ring. The stereochemistry of the desaturation reaction has been explored with L-tryptophan (85) samples stereospecifically labelled with tritium at... [Pg.19]

Svec und Junk (24) haben durch Untersuchung deuterierter Dioxo-piperazine nachgewiescn, daB ca. 20% dcr Iminium-Ionen durch eine zweite einstufige Zerfallsreaktion gebildet werden, bei der cin Wasser-stoff-Atom von einem zum anderen Stickstoffatom wandert ... [Pg.48]

Another route to amino substitution is the exchange of alkoxy or siloxy groups, which arc accessible by Oalkylation, e.g. by a Mitsunobu reaction with methanol,331 or O-silylation of hydroxy or oxo functions.83 Thus, piperazine reacts with 2-alkoxy-8-ethyl-5-oxo-5,8-dihy-dropyrido[2,3-rf]pyrimidine-6-carboxylic acids, e.g. 8,335,336 or with 8-ethyl-2,5-dioxo-l,2,5,8-tetrahydropyrido[2,3-c/]pyrimidine-6-carboxylic acid (9), after silylation by hexamcthyldisila-zane.337 338... [Pg.144]

Die reduktive Aminierung von 3,20-Dioxo-5a- bzw. 5/t-pregnan liefert regiospezifisch und stereoselektiv 3/3-tert. -Amino-20-oxo-5 a - (bzw. 5p)-pregnan (neben geringen Men-gen des 3a-Derivats). Als Amine werden Pyrrolidin, Piperidin, Morpholin und 1 -Methyl- 1,4-piperazin eingesetzt8 z.B. ... [Pg.456]

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