Pyrroles 2-pyrrolidone

An interesting substitution which gives a product (13) related to the Mannich bases, by means of a modified Vilsmeier reaction, occurs between pyrrole, pyrrolidone and phosphoryl chloride . Other examples are known27i, 3i3 ... 

The importance of ring size holds also for tautomerism of -pyrrol-5-ones and. d -dihydro-6-pyridones. While the former compounds behave as cyclic 1-methyl-2-alkyl-2-hydroxy-5-pyrrolidones 179) (76) [or, on distillation, as the dehydrated l-methyl-2-alkyl-J -pyrrolones (77)], the latter compounds exist as acyclic N-methylamides of 8-oxo-acids (78) [as shown by infrared spectroscopy (/80)j. The dehydration of 78 during distillation to form l-methyl-2-alkyl-. -dihydro-6-pyridones (79) is achieved only with difficulty. 

HDZ = hydrazine Igepal CO-520 = polyoxyethylene(5)nonylphenyl ether ISO = isooctane LAc = linoleic acid MA = methylamine MST = mesitylene Ni°(cod)2 = bis (r]4-l,5-cyclooctadiene) Ni(0) NMPyr = N-methylpyrrole OA = oleylamine OAc = oleic acid Oc = octane OcA = octylamine ODA = octadecylamine PAA = poly (acrylic add) PD = 2-pyrrolidone Igepal CA-520 = polyoxyethylene(5)isooctylphenyl ether PVP = polyvinylpyrrolidone Pyr = pyrrole RAc = ricinoleic acid ... 

Although the annelated octahydropyrrolo[2,3-b ]pyrrole unit occurs in the physostigmine-type alkaloids, simple systems were reported only in 1978. DIBAL reduction of the pyrrolidones (348) furnished the octahydropyrrolo[2,3-b jpyrrole derivatives (349 Scheme 120). It is interesting to note that LAH failed to bring about ring closure (78JOC4276). 

L-Theanine is the most abundant amino acid in tea flush. Volatiles produced by pyrolysis at 180°C of (A) L-theanine, (B) (-)-epigallocatechin gallate and (C) a mixture of (A) and (B) were examined. The procedure was the same as that reported earlier for the pyrolysis of 8-carotene. The results of the GC-MS analysis are shown in Figure 4. From L-theanine alone, a large amount of N-ethyl-formamide was formed, along with ethyl amine, propyl amine, 2-pyrrolidone, N-ethyl-succinimide and l-ethyl-3,4-dehydro-pyrrol idone. 

The apparently simple procedures of partial dehydrogenation of pyrrolidines and partial hydrogenation of pyrroles afford Zl1-pyr-rolines. However, the reaction is complex and is of little preparative value.97-98 A 1-Pyrrolines may be obtained by isomerization of A 3-pyrrolines.100 From the preparative point of view, partial hydrogenation of quaternary pyridine salts in strongly alkaline media to give 1-alkyl-id 2-piperideines is more important.101 Formation of heterocyclic enamines was observed in the reduction of i -methyl-pyrrolidone with lithium aluminum hydride,102 -alkylpiperidones with sodium in ethanol,103,104 and in the electrolytic reduction of N-methylglutarimide.106... 

Oxidations with peroxybenzoic acid are carried out in solutions in dichloromethane, chloroform, benzene, ether, or ethyl acetate at or below room temperature and include epoxidation of double bonds [295, 296, 297, 298, 299, 300, 301], oxidation of benzaldehydes to carboxylic acids or phenols [302], the Baeyer-Villiger reaction of ketones [303, 304, 305, 306, 307], and oxidation of sulfides to sulfoxides [308, 309]. Peroxybenzoic acid is also used for the anti hydroxylation of double bonds [310], the oxidation of pyrrolidines to pyrrolidones [377] and of pyrroles to succinimides [377], and the preparation of azoxy compounds from azo compounds [372]. 

These same workers described an inverse emulsion-type polymerization process.109 They used a conventional process in which microemulsions of water in hydrocarbon readily form in the presence of Aerosol-OT(AOT). The droplets are essentially swollen cells, where radius is controlled by the water/AOT ratio. As droplets collide, hydrophilic reagents contained in them are exchanged. When pyrrole and (NH4)2S208 dispersions were mixed, eventually a sediment appeared. However, if poly(vinyl pyrrolidone) (PVP) was added at different intervals, stable dispersions of small particles could be prepared. 

The pyrrolidone side chain is known to be nontoxic e.g. in poly(vinyl pyrrol idone). Incorporation of the dimethylamino-moiety leads to zwitterionic structures such structures are known to lower the toxicity of the polycationic poly(ethyleneimine) (12). 

Pyrolysis and smoke studies of amino acids indicate that they are potential precursors of several nitrogen heterocyclic ring systems found in tobacco smoke. Proline has been shown to be efficiently converted to pyrrole upon pyrolysis (3219, 3724) and in addition has been proposed as a possible precursor of pyrocoll (2593, 4336). y-Amino acids and dicarboxy-lic amino acids are capable, under pyrolytic conditions, of forming 2-pyrrolidones (1967, 3079) and by a similar mechanism, A-amino acids can form 2-piperidones (1967, 3079). A side effect of the pyrolysis of amino acids is the formation of hydrogen cyanide. 

Write structures for the products formed by the reaction of pyrrole with POCI3 in combination with (i) A,A-dimethylbenzamide (ii) pyrrole-2-carboxylic acid A,A-dimethylamide (iii) 2-pyrrolidone —> CgHioN2, in each case followed by aq. NaOH. 

Pyrrolidone-2 a-Pyrrolidone. See2-Pyrrolidone Pyrrolidonecarboxylic acid 2-Pyrrolidone-5-carboxylic acid. See PCA Pyrrolldone, N-octyl-. See Caprylyl pyrrolidone Pyrrolo (3,4-c) pyrrole-1,4-dione, 3,6-bis (4-chlorophenyl)-2,5-dihydro. 

Hydroxy-2-ethyl-4-pyrone. See Ethyl maltol 1-(2-Hydroxyethyl)-2-pyrrolidinone 1-(2-Hydroxyethyl) pyrrolidin-2-one. See N-Hyd roxyethyl pyrrol idone N-Hydroxyethylpyrrolidone CAS 3445-11-2 EINECS/ELINCS 222-359-4 Synonyms 1 -(2-Hydroxyethyl)-2-pyrrolidinone 1-(2-Hydroxyethyl) pyrrolidin-2-one N-(2-Hydroxyethyl)-2-pyrrolidone 2-Pyrrolidinone, 1-(2-hydroxyethyl)-Classification Nonaromatic amide Empirical CsHiiN02... 

Pyrrolidinone, 1-vinyl-, polymer with styrene. See Vinylpyrrolidone/styrene copolymer Styrene/PVP copolymer Pyrrolidone. See 2-Pyrrolidone 2-Pyrrol idone... 

CAS 28874-51-3 (L) 54571-67-4 (DL) EINECS/ELINCS 249-277-1 (L) 259-234-9 (DL) Synonyms 5-Oxo-DL-proline, sodium salt 5-Oxo-L-proline, sodium salt PCA-Na PCA Soda Sodium 5-oxo-L-prolinate Sodium pyroglutamate Sodium DL-2-pyrrolidone-5-carboxylate Sodium L-2-pyrrol idone-5-carboxyl ate Definition Sodium salt of pyroglutamic acid... 

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