Search results
Results from the WOW.Com Content Network
Pyrrole has a nutty odor. Pyrrole is a 5-membered aromatic heterocycle, like furan and thiophene. Unlike furan and thiophene, it has a dipole in which the positive end lies on the side of the heteroatom, with a dipole moment of 1.58 D. In CDCl 3, it has chemical shifts at 6.68 (H2, H5) and 6.22 (H3, H4).
Viktor Meyer was able to isolate thiophene as the actual substance responsible for this reaction. [4] Thiophene and especially its derivatives occur in petroleum, sometimes in concentrations up to 1–3%. The thiophenic content of oil and coal is removed via the hydrodesulfurization (HDS) process.
Included are pyridine, thiophene, pyrrole, and furan. Another large class of organic heterocycles refers to those fused to benzene rings. For example, the fused benzene derivatives of pyridine, thiophene, pyrrole, and furan are quinoline, benzothiophene, indole, and benzofuran, respectively. The fusion of two benzene rings gives rise to a third ...
Furan is a colorless, flammable, highly volatile liquid with a boiling point close to room temperature. It is soluble in common organic solvents, including alcohol, ether, and acetone, and is slightly soluble in water. [2] Its odor is "strong, ethereal; chloroform-like". [3] It is toxic and may be carcinogenic in humans.
This pyrrole was found to be unstable, and as such was treated with trimethylsilyl ethoxy methoxy chloride (SEM-Cl) to protect the pyrrole prior to isolation. Roseophillin Paal-Knorr In 1982, H. Hart et al. reported a synthesis of a macrocycle containing fused furan rings using a Paal–Knorr furan synthesis. [ 16 ]
This page contains tables of azeotrope data for various binary and ternary mixtures of solvents. The data include the composition of a mixture by weight (in binary azeotropes, when only one fraction is given, it is the fraction of the second component), the boiling point (b.p.) of a component, the boiling point of a mixture, and the specific gravity of the mixture.
Heteroarenes are aromatic compounds, where at least one methine or vinylene (-C= or -CH=CH-) group is replaced by a heteroatom: oxygen, nitrogen, or sulfur. [3] Examples of non-benzene compounds with aromatic properties are furan, a heterocyclic compound with a five-membered ring that includes a single oxygen atom, and pyridine, a heterocyclic compound with a six-membered ring containing one ...
A library of substituted pyrrole analogs can be quickly produced by using continuous flow chemistry (reaction times of around 8 min.). [10] The advantage of using this method, as opposed to the in-flask synthesis, is that this one does not require the work-up and purification of several intermediates, and could therefore lead to a higher ...