Pyrrolidine 2-phenyl

Piperidine, 3-aryIoxymethyI-4-phenyI-as antidepressant, 1, 169 Piperidine, JV-bromo-photoelectron spectroscopy, 2, 142 Piperidine, cis-4- t-butyl-r- cyclohexyl-1 -phenyl-X-ray analysis, 2, 161 Piperidine, 3-chloro-pyrrolidines from, 4, 147 Piperidine, N-chloro-photoelectron spectroscopy, 2, 142 reactions, 2, 373 trimerization, 3, 510 Piperidine, 4-cycIopentyI-2,6-dioxo-synthesis... 

Normally, phenylhydrazine reacts with the enol form of 1,1,1-trifluorometh-ylpentane-2,4-dione to give 5-methyl-l-phenyl-3-tnfluoromethylpyrazole as the major product. However, the use of pyrrolidine as a transient carbonyl-blocking group can completely reverse the regiochemistry of the addition and leads to 3-methyl-l-phenyl-5-trifluoromethylpyrazole [102] (equation 88)... 

Reaction of the pyrrolidine enamine of cyclohexanone with phenyl vinyl sulfone afforded a 9 1 mixture of the tri- and tetrasubstituted isomers (2(5). The preference of the less substituted isomer in this case is in keeping with the greater overlap requirement between the n electrons of the double bond and the electron pair on the nitrogen atom, since the double bond exo to the five-membered ring is much more favored than the double bond exo to the six-membered ring. It is, however, hard to explain the formation of largely the trisubstituted isomer with the piperidine enamine of cyclohexanone, where both of the rings involved are six-membered. 

The piperidine, pyrrolidine, and morpholine enamines of cyclohexanone substituted in the 3-position by methyl, phenyl, and l-butyl have been prepared (49). The complexity of the NMR spectra in the ethylenic hydrogen region indicated a mixture of isomeric enamines. Estimation of the per cent of each isomer by examination of the NMR spectra was not possible, nor were the isomeric enamines separable by vapor-phase chromatography. 

The enamines derived from cyclic ketones give the normal alkylated products, although there is some evidence that unstable cycloadducts are initially formed (55b). Thus the enamine (28) derived from cyclohexanone and pyrrolidine on reaction with acrylonitrile, acrylate esters, or phenyl vinyl sulfone gave the 2-alkylated cyclohexanones (63) on hydrolysis of the intermediates (31,32,55,56). These additions are sensitive to the polarity of the solvent. Thus (28) in benzene or dioxane gave an 80% yield of the... 

The acetate (1) and its mosylate analog (79) have been shown to undergo cydoad-dition with the CN double bond of alkyl imines to generate substituted pyrrolidines in the presence of nickel or palladium catalyst [35]. For example, both the phenyl imine (80) and the diazene (81) gave reasonable yields of adducts (82) and (83) respectively (Scheme 2.23). 

A phenyl guanidine analogue is readily prepared by first I i acting 2-imino-]i-methylpyrrolidine with phenyl isothiocyanate III give synthon 21, This is next -methylated with methyl io-illcle to give 16 which itself, on reaction with pyrrolidine, is... 

There is heated under reflux with stirring for 10 hours 117 g of (2-phenyl-2-isoamyloxy )-ethyl bromide, 61 g of pyrrolidine and 250 ml of toluene. 

The starting material is prepared by the reaction of acetophenone, paraformaldehyde and pyrrolidine to give OJ-pyrrolidinopropiophenone. That is in turn reacted with phenyl magnesium bromide to give 1,1-diphenyl-3-pyrrolidinpropan-1-ol. 

Chemical Name 1-[4-(4-Chlorophenvl)-3-phenyl-2-butenvl] -pyrrolidine Common Name —... 

With the amide 8 (R1 = C 11,) derived from 2-oxopropanoic acid and amine E, the (2 R)-diastereomer is predominantly formed, regardless of the solvent, through chelation-controlled Re-side attack of the organometal14. Presumably, the weaker steric interaction between the pyrrolidine moiety and the methyl substituent of the amide (R1 = CH3) compared to the phenyl substituent (R1 = C6H5) facilitates the preferential formation of the chelated conformer S-m-8. 

Optically active 2-allylpiperidines and -pyrrolidines arc obtained by treating hydroxylactams containing the l-[(S)-l-arylethyl]substituent as an auxiliary (see Appendix) with tin(IV) chloride and trimethyl(2-propenyl)silane46. Interestingly, the moderate diastereoselection when the aryl group is phenyl decreases when 2-chlorophenyl is used, whereas the sense of the stereoselectivity reverses for 2,6-dichlorophenyl or pentachlorophcnyl. These results are rationalized by application of molecular orbital theory and substrate conformational preferences46. 

I -Phenyl-pyrrolidin + 4-Anilino-butanol l -tert.-Butyl-pyrrolidin + 4-terl.-Butylamino-butano ... 

Sila-procyclidine, (cyclohexyl)phenyl[2-pyrrolidin-l-yl]silanol, may be prepared by hydrolysis of the corresponding methoxysilane (220) and is interesting in that it can form two types of hydrogen-bonded structure depending on whether it is enantiomerically pure or a racemate. In the racemate, the compound forms centrosymmetric dimers of (R)- and (S)-configuration molecules with an 0---N distance of 1.791 A. In the pure (R)-compound, however, the molecules are linked into infinite chains via intermolecular 0-H---N hydrogen bonds (0---N distance 2.792 A) (221), again similar to those in (2-morpholinoethyl)diphenylsilanol shown in Fig. 3. 

Several analogues of PCP with similar pharmacological effects are available on the streets. These include PCE (cyclohexamine), PHP (phenyl - cyclohexyl-pyrrolidine, PCPP (phenyl -cyclo-pentyl-pi peri -dine), and TCP (thienyl-cyclohexyl-piperidine) (Baselt 1982). 

Recently, SB-269970 (l-[3-hydroxy-phenyl-sulphonyl]-2-[2-(4-methyl-l-piperidinyl)-ethyl] pyrrolidine) and SB-656104 (6-((R)-2- 2-[4-(4-chloro-phenoxy)-piperidin-l-yl]-ethyl pyrrolidine-l-sulphonyl)-lH-indole) have been reported to be potent 5-HT7 receptor antagonists (Hagan et al., 2000 Forbes et al., 2002). Selective 5-HT7 receptor agonists are not available at the present time. Systemic administration of SB-269970 or SB-656104 to rats at the beginning of the light period has been shown to reduce the total amount of REMS and to increase REMS latency. Values of W and SWS were not significantly modified (Hagan et al., 2000 Thomas et al., 2003). Hedlund et al. (2005) established that 5-HT7... 

Diastereomerically pure (2W,5.V)-l,3-diaza-2-(2-methylphenyl)-3-phenyl-2-phosphabicyclo[3.3.0]octane (.S )-202] was formed in the thermal reaction of (S)-2-(anilinomethyl)pyrrolidines (197a) with o-TolP(NMe2)2 and isolated in 27% yield after recrystallization (Scheme 56) [87], Its cyclopalladation with palladium diacetate followed by anion metathesis gave dimer (5,5)-203 (Scheme 56) [87],... 

More recently, Kaiser and coworkers reported enantiomeric specificity in the reaction of cyclohexaamylose with 3-carboxy-2,2,5,5-tetramethyl-pyrrolidin-l-oxy m-nitrophenyl ester (1), a spin label useful for identifying enzyme-substrate interactions (Flohr et al., 1971). In this case, the catalytic mechanism is identical to the scheme derived for the reactions of the cycloamyloses with phenyl acetates. In fact, the covalent intermediate, an acyl-cyclohexaamylose, was isolated. Maximal rate constants for appearance of m-nitrophenol at pH 8.62 (fc2), rate constants for hydrolysis of the covalent intermediate (fc3), and substrate binding constants (Kd) for the two enantiomers are presented in Table VIII. Significantly, specificity appears in the rates of acylation (fc2) rather than in either the strength of binding or the rate of deacylation. 

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