Pyrrolidine perchlorate

Anhydrous acetone added to pyrrolidine perchlorate, swirled, and the product isolated after a few min. 

Mesityl oxide and pyrrolidine perchlorate in ethanol containing a few drops of pyrrolidine allowed to stand 36 hrs. at 25°... 

Reduction of l-methyl-2-alkyl-.d -pyrroline and l-methyl-2-alkyl-.d -piperideine perchlorates with complex hydrides prepared in situ by partial decomposition of lithium aluminum hydride with the optically active alcohols (—)-menthol and (—)-borneol affords partially optically active l-methyl-2-alkyl pyrrolidines (153, n = 1) and 1-methy 1-2-alkyl piperideines (153, n = 2), respectively (241,242). 

Last but not least, a very intriguing terpenoid pyrrolidine alkaloid, poly-zonimine was milked from the millipede Polyzonium rosalbum (148). The structural formula of polyzonimine (118) is based on an X-ray crystallographic analysis of its perchlorate and by a total synthesis. 

Phenyl 2,6-dinitro-4-trifluoromethylphenyl sulphide. Chamberlain and Crampton130 studied also the reaction of phenyl 2,6-dinitro-4-trifluoromethylphenyl sulphide with amines in DMSO. They observed a single rate process with butylamine giving the expected substituted product again, the observed rate constant increased with [butylamine]. In the reaction with pyrrolidine a rapid reaction giving the 3-pyrrolidino adduct was observed, which could be suppressed by addition of pyrrolidinium perchlorate. Under these conditions the expected 1-substituted product was formed. 

Cervinka has employed these reagents in the asymmetric reduction of im-monium salts (49,50) and imines (51). The reduction of 2-substituted jV-methyl-A -tetrahydropyridinium perchlorates (10) with (— )-menthol-LAH in ether or THF led to optically active piperidine derivatives (eq. [10]). The optical purity obtained for the Pr" derivative was 12%. In the case of R = Me and Pr" the configuration of the predominant enantiomer was shown to be S. The (-)-menthol-LAH reagent was similarly shown to reduce l-methyl-2-alkyl-A -di-hydropyrrolinium perchlorates (11) to optically active pyrrolidine derivatives (eq. [11]). The optical yield could be calculated only for R = CH2Ph, and was only 6% (/ enantiomer) obtained with a 1 1 (— )-menthoi-LAH reagent. With 2 1 or 3 1 molar ratios of menthol LAH, the optical yield decreased. The... 

Official methods have been published for the determination of nitric-perchloric acid-soluble lead [111] and ammonium pyrrolidine dithiocarbamate-extractable lead [ 112] in soil. Atomic absorption spectrometric evaluations of the digest or extract is conducted at the 217 nm emission line from a lead hollow cathode lamp. Rigin and Rigina [122] determined lead in soil by flameless atomic fluorescence using electrolytic preconcentration. The limit of detection is 15 pg lead and the standard deviation is not greater than 0.04. 

Standard official methods have been described for the determination of nitric-perchloric acid-soluble nickel [174] and acetic acid-extractable nickel [175] in soil. To determine nitric acid-perchloric acid-soluble nickel [174], the acid digest is dissolved in hydrochloric acid and the nickel is determined by atomic absorption spectrometry. To determine extractable nickel, the nickel is first extracted from the soil with 0.5 M acetic acid and the nickel is then converted to the ammonium pyrrolidine dithiocarbamate complex. Extraction of the complex with chloroform provides an extract for the determination of nickel by atomic absorption spectrometry. 

Cyclization of a,abis(dimethylthiomethylene) ketones by phosphorus pentasulfide leads to 2,5-bis(methylthio)-l,6,6aA4-trithiapentalenes (equation 7) (71AHC(13)161, p. 185). Condensation of carbon disulfide with pyrrolidin-2-one in basic medium, followed by methylation of the reaction product, leads to methyl 3-(dimethylthiomethylene)-2-oxopyrrolidine-l-dithiocarboxylate. This compound, when treated with phosphorus pentasulfide and perchloric acid, yields the 2,5-bis(methylthio)-l,6,6aA4-trithia-2aA5-azacyclopenta[a/]pen-talen-2a-ylium cation. With e- caprolactam similar results are obtained (76BSF1200). 

Illustrative of the chemistry of the aminyl radical is a synthesis of the A -methyl derivative of the antibiotic (—)-anisomycin (73) [20]. It was obtained by treating (E )-5-alkenylamine 71 with -butyllithium at —78°C, followed by anodic oxidation at a constant current (17.5mA/cm") in a 100 1 mixture of tetrahydrofuran (THE) and hexamethyl-phosphor-ous-triamide (HMPA) containing 0.25 M lithium perchlorate at — 10°C. A 5-exo,trig cycli-zation of the metalated aminyl radical afforded pyrrolidine 72 as a single isomer in a 53% yield. A routine series of transformations converted 72 to the target structure 73. 

To a solution of l-chloro-2,3-bis(diisopropylamino)cyclopropenylium perchlorate (3.7t g, 10 mmol) in EtOH (10 mL) was added dropwise pyrrolidine (2.0 g, 28 mmol). After the exothermic reaction subsided, the solvent and excess pyrrolidine were evaporated and the residue was taken up in CHjClj (20 mL). The CH2CI2 solution was washed with HjO (2 x 50 mL), dried (Na2S04), and diluted with EtjO which resulted in the precipitation of colorless crystals (CH2Cl2/Et20) yield 3.1 g (77%) mp 136-138 C. 

Although dihydropyrans (48) are formed from MVK and enamines at low tempera-tures S in refluxing benzene the pyrrolidine enamine of isobutyraldehyde gives tricyclic ketone 51 (R = Me) via the intermediacy of the cross-conjugated dienamine 49 " and of 50 (Scheme 27). A similar product to 50 but without the geminal methyl groups was obtained by self-condensation of cyclohex-2-enone in the presence of pyrrolidinium perchlorate ... 

The d/-ketone (5) did not form an enamine readily but was resolved by dissolving 7.7 g. in hot absolute ethanol (45 ml.) and adding 6.4 g. of pyrrolidine perchlorate3 and 2 drops of pyrrolidine. The enamine perchlorate that crystallized was collected and treated with potassium d-camphor-10-sulfonate in absolute methanol. Crystallization then gave enantiomeric salts and from them the (+) and (—) ketones were recovered. 

Enamines [after citation of ref. 4], Gadsby and Leeming43 used eniminium salts for protection of a A4-3-keto grouping of steroids. The enamine (2) is formed as usual from pyrrolidine and treated with a strong acid such as hydrochloric or perchloric acid to form the eniminium salt (3). Various electrophilic reactions at C 7 or... 

A A -Dialkylarylamines react under classical conditions at C-4 if that position is unsubstituted. For example, A. )V-dimethylaniline reacts with formaldehyde and dimethylamine to afford 4-)V, A -dimethyl-amino-A, Af-dimethylbenzylamine in 82% yield (equation 20). Under acidic conditions fragmentation of the initial product can occur, leading to the formation of diarylmethanes. In the reaction of A A -dimethy-laniline with formaldehyde and pyrrolidine the best yield of the Mannich base (44%) is obtained in the presence of 1.5 mol equiv. of acetic acid with 4.0 mol equiv. the yield is only 7%. The reaction of N-methylenemorpholinium chloride with 4-A -morpholinylmethyl-)V,A -dimethylaniline results in the introduction of a second A -morpholinylmethyl residue at the 2-position, but with other iminium chlorides quaternary salts are formed by reaction with the nitrogen of the 4-dialkylaminomethyl group. There is dso a brief report of the use of the mixed A. Af-dialkylmethyleneiminium salt, A -f-butyl-A -methyl-methyleneiminium perchlorate, with A. Af-dimethylaniline. °... 

Condensation of carbonyl compounds with secondary amines such as morpholine and pyrrolidine, introduced as perchlorates, gives the iminium salts in high yield 890... 

Dabeka RW and McKenzie AD (1986) Graphite-furnace atomic absorption spectrometric determination of lead and cadmium in food after nitric-perchloric acid digestion and copredpitation with ammonium pyrrolidine dithiocarbamate. Can J Spectrosc 31 44-52. 

When a mixture of acetic anhydride and trimethylsilyl triflate was used, the opening of the Cl - O bond took place to yield the corresponding acy-lated polyhydroxy pyrrolidines 11 as mixtures of a- and b-anomers [43], compounds of interest as potential glycosidase inhibitors. However, when the opening of the pyranose ring is carried out in methanol containing lithium perchlorate, followed by addition of a 2 1 mixture of TFA and trifluoroacetic anhydride, only 12 was obtained as a single diastereoisomer (Scheme 4). 

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