Pyrrole


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pyrrole

[′pi‚rōl]
(organic chemistry)
C4H5N Water-insoluble, yellowish oil, with pungent taste; soluble in alcohol, ether, and dilute acids; boils at 130°C; polymerizes in light; used to make drugs.

Pyrrole

 

a heterocyclic compound; colorless liquid that darkens rapidly upon exposure to air. Melting point, — 23.42°C; boiling point, 130°C; density, 0.9698 g/cm3 at 20°C. Moderately soluble in water. Pyrrole is a very weak acid; it forms a salt with potassium or anhydrous caustic potash. It resinifies under the influence of acids, and it oxidizes readily. It hydrogenates with H2 over Ni at 200°C to pyrrolidine.

Pyrrole was first isolated from coal tar. It is produced commercially

by dry distillation of the ammonia salt of mucic acid or by passing a mixture of furan and NH3 over Al2O3 at 400°–450°C. The pyrrole nucleus is a structural fragment of porphyrin molecules. Pyrrole is used in the production of pyrrolidine and in the synthesis of pharmaceuticals—for example, the antiseptic Iodol (2,3,4,5-tetraiodopyrrole).

References in periodicals archive ?
In this paper, the novel rhodamine-based fluorescent chemosensor XQN was designed and synthesized (Scheme-1), which was modified by pyrrole structure with amide to improve increase the selectivity of rhodamine-6G dye.
In this case, pyrroles, neonicotinoids, and spinosyns may be used in rotation to control both C.
Four characteristic peaks could be assigned to C=C stretching vibration of the pyrrole ring, C-N stretching vibration in the ring, and C-H in-plane vibrations, respectively.
The electrical conductivity of the nanocomposites as a function of concentration of pyrrole and the molar ratio used in the reactions are shown in Table 1.
Therefore, in a chemical oxidative polymerization of pyrrole monomer, many researchers have reported using different oxidants for synthesizing PPy.
Pyrrole, 1, and pyrazine, 1d, 1a-c, and 1e, which may be treated as fragments of these systems, are also analyzed for comparison.
Hydrazine hydrate, phosphate buffer solution, pyrrole, graphene oxide, and butylated hydroxytoluene were obtained from Sigma-Aldrich (MO, USA).
Since 2000, several new non-repellant soil termiticides have been introduced on the market, such as Fipronil, a phenyl pyrazole (Aventis Corp, 2001), Imidacloprid, a chloronicotinyl (Bayer Corp, 2000), and Chlorfenapyr, a pyrrole (BASF Corp, 2001).
[9] performed ab initio calculations using the density functional theory (DFT) to investigate the pyrolysis mechanism of pyrrole, and proposed the mechanism responsible for the formation of allyl cyanide, a major product formed during the decomposition of pyrrole.
The spectra of this peak was matched against the NIST library and the probability of the match suggested it was likely methyl pyrrole.
Pyrrole (Py, Aldrich) was purified in a neutral alumina column and stored under nitrogen in the dark, Poly(sodium-4-styrenesulfonate) (PSS, average molecular weight 70000, Aldrich), lithium perchlorate (LiCl[O.sub.4], J.
The gas phase ligand molecule of tetramic acid (Figure 4(a)) is not planar as the calculated dihedral angle between the phenyl and pyrrole ring is about 31[degrees], in accordance with the crystalline structure where there is a twist of 27.42 (8)[degrees] between the mean planes of the two rings.