Piperazines monoalkyl

Benzhydrylamine Derivatives Attachment of piperazine nitrogen directly to a benzhydryl carbon leads to a pair of compounds which show vasodilator activity, and which should be useful in disease states marked by impaired blood circulation. Reaction of piperonyl chloride (18) with a mixture of piperazine and piperazine dihydrochloride leads to the monoalkylation product (19). (It may be supposed that the mixture of free base and salt equilibrates to the monobasic salt, thus making the second amine less nucleophilic.) Alkylation of 19 by means of benzhydryl chloride then... 

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

Hexahydro-l,3-diazocin-2(l -one (22) is monoacylated to (23) upon treatment with an aromatic acyl chloride (Scheme 6) <83USP439l75l>. Similar nucleophilic behavior is noted in the Mannich reaction of (22) with formaldehyde and various secondary amines, affording poor yields (5 9%) of the monoalkylated products (24 RH = morpholine, piperidine, pyrrolidine, piperazine) ( heme 6). Both nitrogens of piperazine apparently react, affording a bis(perhydrodiazocino) product <88MI 922-01>. 

Uses IWg. of benzyl compds., perfumes, pharmaceuticals, dyes, syn. tannins, artificial resins, bactericides, fungicides, flavors, insecticides, lubricants, plastics, plasticizers, quat. ammonium compds. photography gasoline gum inhibitors penicillin precursors chem. intermediate for n-butyl benzyl phthalate, other benzyl phthalates mbber accelerators pickling inhibitors blocking agent to prepare monoalkylated piperazine formerly as irritant gas in chemical warfare Regubtisy SARA 313 reportable... 

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