Heterocyclic Chemistry: The Knorr Synthesis of Pyrroles Essay

Heterocyclic Chemistry: The Knorr Synthesis of Pyrroles Essay

Length: 2349 words (6.7 double-spaced pages)

Rating: Term Papers

Open Document

Essay Preview

The Knorr synthesis of the pyrrole, 2,4-diethoxycarbonyl-3,5-dimethylpyrrole, was achieved using an α-amino ketone, ethyl acetoaminoacetate and reacting it with its predecesso r, ethyl acetoacetate in a double condensation reaction . The product was analysed by 1H NMR, 13C NMR, mass spectrometry and IR spectroscopy giving positive results .
Pyrrole has been a molecule of great interest due to its heterocyclic aromatic properties. The lone pair on the nitrogen is delocalised within the ring, causing the heterocycle to be electron-rich . This causes the ring to become increasingly nucleophilic, and therefore makes it susceptible to attack from electrophiles . The addition of these new substitutions makes more important molecules , which have a huge contribution to not only the chemical industry, but also the biological. 1 Substituted pyrrole molecules are fantastic precursors to make complex molecules, such as medicines, agrochemicals and dyes. Indole, an important benzo-pyrrole, is the basis of the important protein, tryptophan and has functions as a neurotransmitter in the brain. The neurotransmitter, serotonin, is important in making modern drugs such as sumatriptan which treats migraines.2

Pyrrole synthesis can be achieved by a vast number of methods. Some of the most common processes used in today’s laboratory include the Hantzch pyrrole method, Paal-Knoor Knorr synthesis and the Knoorr synthesis; the latter which will be studied in this experiment. Other complex methods explored include Robinson’s utilization of the reaction between an aldehyde and a hydrazine . However, this method requires high temperatures which are not economically favourable to maintain and so the other classic methods are gene...

... middle of paper ...

...ential of the reaction and products.


Works Cited
1. V. Amarnath, D. C. Anthony, K. Amarnath, W. M. Valentine, L. A. Wetterau, D. G. J. Org. Chem. 1991, 56, p. 6924-6931.
2. J. Clayden, N. Greeves, S. Warren, P. Wothers. Organic Chemistry. 8th ed. 2007, Oxford University Press, p. 1186-1191.
3. G. M. Robinson, R. Robinson. J. Chem. Soc. 1918, p. 639-645.
4. A. H. Corwin. Heterocyclic Compounds. 1950, 1, p. 287.
5. Y. Byun, D. A. Lightner. J. Heterocyclic Chem. 1991, 28. p. 1683-1692.
6. Professor Chris Willis, School of Chemistry, University of Bristol
7. Professor Kevin Booker-Milburn, 2nd Year Heterocyclic notes, School of Chemistry, University of Bristol
8. H. Fischer. Organic Syntheses Coll. 1943, 2, p. 202; H. Fischer. Organic Syntheses Coll. 1935, 15, p. 17.
9. C. Schmuck, D. Rupprecht. Synthesis 2007, 2007, 20, p. 3095-3110.

Need Writing Help?

Get feedback on grammar, clarity, concision and logic instantly.

Check your paper »

Essay on The Knorr Synthesis of Pyrroles

- The Knorr Synthesis of Pyrroles Experimental A mixture of ethyl acetoacetate 1 (7.52 g, 7.5 mL) in glacial acetic acid (18 mL) was prepared and cooled to 5oC while stirring. Sodium nitrate solution (2.1 g in 5 mL deionised water) was added at such a rate that the temperature of reaction did not exceed 7oC. Once this addition was complete the mixture was stirred with cooling for 10 minutes before being allowed to warm to room temperature. Zinc dust (4.0 g) was added to the reaction mixture in small portions so that the mixture refluxed gently, the reaction mixture was then heated to reflux for one hour....   [tags: Chemistry]

Term Papers
978 words (2.8 pages)

How to Write a Synthesis Essay

- The main purpose of a synthesis essay is to make insightful connections. Those connections can show the relationship(s) between parts of a work or even between two or more works. It is your job to explain why those relationships are important. In order to write a successful synthesis essay, you must gather research on your chosen topic, discover meaningful connections throughout your research, and develop a unique and interesting argument or perspective. A synthesis is not a summary. A synthesis is an opportunity to create new knowledge out of already existing knowledge, i.e., other sources....   [tags: Synthesis Essay]

Free Essays
1666 words (4.8 pages)

How to Write a Synthesis Essay

- 1. What is a synthesis. A synthesis is a written discussion incorporating support from several sources of differing views. This type of assignment requires that you examine a variety of sources and identify their relationship to your thesis. 2. Synthesis is used in: Analysis papers to examine related theories. For example a comparison between the theories of evolution or who shot JFK. Research papers to incorporate multiple sources. For example looking at economic and social effects of proposed legislation....   [tags: Synthesis Essay]

Free Essays
390 words (1.1 pages)

How to Write a Synthesis Essay

- What is a synthesis essay. A synthesis essay draws on two or more sources and combines their ideas into a coherent whole. What do I need to write one. Writing a successful synthesis essay will require you to do four things: read accurately and objectively, see relations among different viewpoints, define a thesis based on these relations, support the thesis effectively. You will not discuss all the points in every essay; but you should use every essay assigned, and you should use points from each that are appropriate for the thesis of your own essay....   [tags: Synthesis Essay]

Free Essays
510 words (1.5 pages)

Synthesis Of Multicomponent Reactions Using Nanomagnetic Catalyst Under Solvent Free Condition

- 1. Nanomagnetic-supported sulfonic acid is found to be a powerful and reusable heterogeneous catalyst for the efficient synthesis of Pyrimidinones. In this study we use various ketones such as acetophenone and cyclopentanone in one-pot synthesis of Pyrimidinones. Our objective is to improve conditions for the synthesis of multicomponent reactions using nanomagnetic catalyst under solvent free condition. A Number of excellent and significant results have been developed that lead our perspective understanding of the effect of the magnetic nanoparticles when they are used as catalysts....   [tags: Chemistry, Chemical reaction, Catalysis]

Term Papers
1109 words (3.2 pages)

Writing a Synthesis Essay

- A synthesis essay should be organized so that others can understand the sources and evaluate your comprehension of them and their presentation of specific data, themes, etc. The following format works well: The introduction (usually one paragraph) 1. Contains a one-sentence statement that sums up the focus of your synthesis. 2. Also introduces the texts to be synthesized: (i) Gives the title of each source (following the citation guidelines of whatever style sheet you are using); (ii) Provides the name of each author; (ii) Sometimes also provides pertinent background information about the authors, about the texts to be summarized, or about the general topic from which the...   [tags: Synthesis Essay]

Free Essays
442 words (1.3 pages)

A General Review of the Chemistry and Utility of Scopolamine Essay

- The study of scopolamine involves aspects that are manifold and complex. In this investigation, the pathways for biological and laboratory syntheses were elucidated, in additional to the physical and chemical properties and characteristics of scopolamine. 13C-NMR and H-NMR were generated from collected data, and the isolation and uses of scopolamine were discussed. Introduction Scopolamine's uses have roots in ancient times and have pervaded into the present. This heterocyclic tropane alkaloid is naturally found in Solanaceas plants and can be prepared in the laboratory from various precursors....   [tags: Chemistry]

Term Papers
2380 words (6.8 pages)

Essay Nuclear Chemistry

- Types of Radiation: • List the three types of Radiation and describe conditions under which each case occurs. Alpha, Beta, Gamma. Alpha radiation/emission - Alpha particles are the nuclei of a Helium atom 42He. Consisting of two protons and two neutrons, positively charged. The nuclei are ejected from heavy, unstable nuclei so as to remove excess protons and neutrons. However, the formed nuclei may still be radioactive in which even further decay will occur. Alpha emissions occur in nuclei with atomic numbers greater than 83....   [tags: Chemistry]

Term Papers
1999 words (5.7 pages)

Organic Chemistry Essay

- Chemistry has been called the science of what things are. Its intent is the exploration of the nature of the materials that fabricate our physical environment, why they hold the different properties that depict them, how their atomic structure may be fathomed, and how they may be manipulated and changed. Although organic reactions have been conducted by man since the discovery of fire, the science of Organic chemistry did not develop until the turn of the eighteenth century, mainly in France at first, then in Germany, later on in England....   [tags: Chemistry]

Term Papers
1119 words (3.2 pages)

Protein Synthesis Essay

- Protein Synthesis Protein synthesis is one of the most fundamental biological processes. To start off, a protein is made in a ribosome. There are many cellular mechanisms involved with protein synthesis. Before the process of protein synthesis can be described, a person must know what proteins are made out of. There are four basic levels of protein organization. The first is primary structure, followed by secondary structure, then tertiary structure, and the last level is quaternary structure. Once someone understands the makeup of a protein, they can then begin to learn how elements can combine and go from genes to protein....   [tags: Protein Synthesis Biology DNA Essays]

Term Papers
787 words (2.2 pages)