Piperazine analogs

Several cyclic glyphosate analogs related to this series were described previously as intermediates to prepare glyphosate. These include various N-phosphonomethylhydantoins and diketopiperazines. A more extended glyphosate piperazine analog 106 has also been prepared firom the Mannich reaction of ethylenediamine-lV,lV -diacetic acid (65). 

The observed regioseleetivity was attributed to a transition state in which the mercuric ion is coordinated to both the N atom and the axially oriented O atom. Using this method Hoornaert and coworkers have synthesized several substituted piperidines and their bicyclic piperazine analogs [231, 234, 235],... 

N-1 Aminoalkyl Chain A number of indole analogs bearing different aminoalkyl substituents at N-1 were synthesized (N-attached analogs, e.g., 34, Fig. 9) and tested (Eissenstat et al. 1995). This study found the aminoethyl substitution as an optimal requirement with morpholino, thiomorpholino, and piperidino analogs showing the highest activities. The respective acyclic amine and piperazine analogs were inactive. 

Piperazine analogs of raloxifene were described by the Shanghai Institute for Biological Sciences [124]. The unsubstituted piperazine 94 showed 19-fold selectivity... 

We were interested in determining whether this requirement held also for the structurally simpler compounds of Mirasan class. We focused our attention on Mirasan itself and the piperazine analog S-688 and prepared the corresponding hydroxymethyl derivatives both by purely chemical and microbiological methods. Before biological evaluation we predicted that Mirasan would be more effective in the mouse than in the hamster because of the much greater quantities of the corresponding hydroxylated metabolite in the urine of mice medicated with Mirasan than in the urine of hamsters treated similarly. 

Alkylation of the p-chloro analog (102) of the monosubsti-tuted piperazine with m-methylbenzyl chloride (103) yields the... 

Alkylation of phenothiazine with l-chloro-2-methyl-3-bromopropane affords the methylated analog (80) of the intermediate above. Use of this halide to alkylate the piperazine... 

Replacement of the terminal nitrogen of the piperazine by carbon is said to enhance the antiemetic activity of the phenothiazines at the expense of the other pharmacologic effects. The simplest compound in this series, pipamazine (88), is prepared by alkylation of nipecotamide (87) with the chloropropyl phenothiazine (58). Preparation of the analogous sulfoxide begins with acetylation of the thiomethyl compound, 89 [prepared by a route... 

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 ... 

Diphenyl-1,2-dihydro-pyrazin wird dagegen unter analogen Bedingungen zum 2,5-Diphenyl-piperazin reduziert (s. S. 584) analog verhalten sich 2,3-Dihydro-l,4-diaz-epin-Derivate (S, 585). 

Polystyrene-supported deoxyribonucleoside-3 phosphoramidites (160), or analogous compounds bound to the support via a piperazine... 

In an analogous sequence, condensation of piperazine with 4,4 -difluorobenzhydryl chloride gives the monoalkylation product (22). Reaction of... 

The presence of a rather more complex substituent on the remote piperazine nitrogen atom is consistent with tranquilizing activity. The preparation of one such agent, 16, begins with reaction of thioxanthone 11 (obtained by a sequence analogous to that used to... 

An analogous approach has been utilized to generate the central piperazine ring of 337 via dimerization of 5-amino-4-bromo-2-phenyl-2,4-dihydro-pyrazol-3-one 336 under basic conditions in good yield (Equation 91) <2003HAC211>. 

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