This website uses cookies to ensure you have the best experience. Learn more

The Knorr Synthesis Of Pyrroles Essay

1011 words - 4 pages

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.
The mixture was then allows to cool and the excess zinc to settle. While still hot the solution was decanted into stirred cold water (200 mL) precipitating the crude product. The zinc residue was washed with warm glacial acetic acid (2 x 5 mL) and this was added to the aqueous solution.
This suspension was allowed to stand for 10 minutes, before being filtered, washed (water 2 x 10 mL) and air dried. The crude product was recrystallised from ethanol to yield a yellow solid 3. 26% yield (1.83 g); Elemental analysis for C12H17NO4: C: 54.918%, H: 6.704%, N: 5.122% (Theoretical: C: 60.24%, H: 7.16%, N: 5.85%, Loss:26.75%); Mr 239.2 g mol-1; ν/cm-1: 1259.48 (N-C), 1667.41 (C=C), 1688.41 (C=O), 2976.58 (C-H), 3265.02 (N-H); 1H-NMR (400 MHz, CDCl3), δ/ppm: 1.24 and 1.38 (dt, 3H, C-CH3, C12 and C15), 2.51 and 2.56 (ds, 6H, 2 x =C-CH3, C6 and C7), 4.31 (m, 4H, 2 x -CH2-, C11 and C14), 5.3 (s, 1H, N5-H); 13C-{1H}-NMR (400 MHz, CDCl3), δ/cm-1:11.98 (C6 and C7), 14.43 (C12 and C15), 59.50 and 60.29 (C11 and C14), 133.5 (C3), 117.5 (C1), 131.3 (C2), 138.6 (C4), 165.47 (C8 and C9) .

Results and Discussion
Product 3 was formed in a low yield of 27% this is probably due to the loss during purification of the product but may also be due to the short amount of time the reaction was allowed to proceed for. To improve on this the reaction should be left longer before quenching and more care should be taken when transferring and during recrystallisation of the crude product.
The overall scheme (scheme 1) and mechanism (scheme 2) of the reaction are shown below:

Scheme 1 The reaction scheme taking place in the experiment outlined above – synthesis of 3.

Scheme 2 The reaction mechanism for the addition of 1 and 2 to give product 3.
The 1H-NMR spectrum of product 3 (fig. 2) shows obvious solvent impurity peaks at 3.73 ppm due to enthanol1 and 2.17 due to acetone1. However, if these are ignored the spectrum shows characteristic peaks of the product; the first of which are at 1.24 (3H) and 1.38 (3H) ppm and are due to the two methyl groups on the ester groups (C12 and C15, fig. 1)2, these partially cover the other small peaks due to ethanol at 1.25 and 1.32 ppm1. The next peaks due to the product are at large singlets at 2.51 (3H) and 2.56 (3H) ppm which correspond to the two...

Find Another Essay On The Knorr Synthesis of Pyrroles

Synthesis of The Reading-Writing Connection and Literary Borrowing

1749 words - 7 pages Lancia’s quote from his article that was included in this synthesis. Her inclusion of a piece of Lancia’s article is just more evidence that both authors agree on the importance and strength of the reading-writing connection that teacher’s must introduce and include within their instruction. In conclusion, both articles provide strong evidence in which students need to be immersed to a high degree in meaningful, purposeful, high quality literature

The Application of Multi-Touch Interfaces Alongside the Live Synthesis and Manipulation of Sound

2616 words - 10 pages in sound synthesis and manipulation There are few MTI’s available in the Music Technology market the best known of which is the Lemur by Jazzmutant it has a fully customisable interface and can work with a number of DAW’s. http://www.jazzmutant.com/lemur_overview.php There is also a very interesting guitar based synthesiser called the Misa Digital guitar it works on the same basic fretting principle of a standard guitar however rather than

integration and synthesis of three grounded theories and conceptual principles of the educational leadership field

3643 words - 15 pages Introduction The objective that I have for this paper is to present the integration and synthesis of at least three grounded theories and conceptual principles of the educational leadership field. Then, according with guidelines, I will compare and contrast those theories by using different authors’ perspectives, to critically analyze the body of knowledge achieved by those principles and explain how those theories in educational leadership add

A critique of the “NCHRP Synthesis 397: Bridge Management System for transportation agencies Decision Making”

1567 words - 6 pages During the period after the collapse of the I-35W BRIDGE in Minnesota, the National Cooperative Highway Reset Program(NCHRP) published a synthesis about bridge management system and decision making that need to be applied across the country. The collapse has awakened public and private agencies in charge so that they begun a new era characterized by paying much attention on their career. A synthesis made by The National Cooperative Highway

An Investigation into the Identification, Properties, and Synthesis of an Unknown Ionic Compound

1186 words - 5 pages Abstract This paper describes the methods used in the identification, investigation of properties, and synthesis of an unknown compound. The compound was identified as calcium nitrate by a variety of tests. When the compound was received, it was already known to be one of twelve possible ionic compounds. The flame test identified the presence of the calcium anion in the compound. The compound tested positive for the nitrate cation using the

This is lab report about The Synthesis and Determination of Empirical Formula for Magnesium Oxide

517 words - 2 pages The Synthesis and Determination of Empirical Formula for Magnesium OxideAim:To determine the empirical formula for magnesium oxide.Data Collection:Table 1 Mass of empty crucible, crucible + Mg (roughly 1cm pieces of a 15-cm piece of magnesium ribbon), and crucible +MgxOy. (mass measured with an analytical balance). The mass of crucible + MgxOy was obtained after a continuous process of heating, letting cool, heating with water enough to immerse

Synthesis of Carbon Nanotubes at Low Temperatures Using Single Heating Source of Catalyst and Reactor in the Floating Catalyst Chemical Vapor Depositi

1088 words - 4 pages Synthesis of carbon nanotubes at low temperatures as low as 540oC was demonstrated via floating catalyst chemical vapor deposition method. Catalytic decomposition of benzene was employed using ferrocene as a catalyst precursor. In this work, the technique of introducing catalyst particles into the reactor has been developed by using single heating source for both the catalyst and reactor. In-situ monitoring device was attached to the CVD unit to

"The Europeans" by Henry James: To what extent is "The Europeans" an expression of James's quest for a synthesis of the two qualities, the 'good' (Americans) and the 'beautiful' (Europeans)?

1342 words - 5 pages In "The Europeans", the Americans (symbolized by the Wentworths) are Puritans who abide by strict Puritan rules, which promote the Puritan way of life. The Europeans, on the other hand (symbolized by Eugenia and Felix), are not Puritans but are sophisticated, opportunistic, and sometimes lax in their way of life. This sometimes causes confusion and conflict when their lives are enmeshed. But it also sometimes brings about an understanding

children towards advertisement

1057 words - 5 pages favorite television program every day. Most of this viewers are children, therefore children become the main target because they are easier to influence. One bad thing about TV advertisements is that is a reason why children are becoming obese. Caroline Knorr explain in her article “Commercialism: Keeping Kids Safe and Savvy” how in the US one out of three children are in risk for becoming obese (par. 1). This means that kids in every family are

Media Violence in The United States

835 words - 4 pages because kids tend to imitate what they see so it is best keep children away from anything that shows any type of physical aggression.It is also hard to keep children away from media violence when so much of the media we use contains some form of violence.Nearly ninty percent of movies, sixty-eight percent of video games,sixty pecent of television shows,and fifteen percent of music videos contain some form of media violence(Knorr).Media violence

The Theme of Escape in The Glass Menagerie

2000 words - 8 pages . Living in the past is Amanda’s way of escaping her pitiful present reality (Knorr). She never forgets to tell Laura and Tom about her receiving seventeen gentlemen callers in Blue Mountain when she was young: "One Sunday afternoon-your mother received-seventeen!-gentlemen callers! Why, sometimes there weren't enough chairs enough to accommodate them all" (Williams 26). She talks about how all her admirers turned out and even though many became

Similar Essays

Heterocyclic Chemistry: The Knorr Synthesis Of Pyrroles

2381 words - 10 pages 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 . Introduction Pyrrole has been a molecule of great interest due to its heterocyclic aromatic properties

The Aldol Condensation: Synthesis Of Dibenzalacetone

1002 words - 4 pages Objective:The benefit of this lab was to acquaint oneself with the fundamentals of the Aldol Condensation reaction by demonstrating the synthesis of dibenzalacetone (trans, trans-1,5-Diphenyl-1,4-pentadien-3-one) through the aldol condensation of acetone with benzaldehyde. The synthesis began by using a strong base to generate the acetone enolate ion. The ketone/enol tautomerization is an equilibrium process that produces little of the enol (ppm

Translation And Protein Synthesis The Role Of Various Rna And The Process Of Synthesis

709 words - 3 pages The process of protein synthesis is vital in organisms, and the release of different types of polypeptides from ribosomes all over the body links genotype to phenotype in the resulting organism. The individual types of RNA (ribonucleic acid) each play their own very important role in going from DNA coding to the final release of a protein chain. Translation itself is the process that makes the distinct change from the information in the nucleic

Comment On The Phylosophical Synthesis Of Karl Marx

5790 words - 23 pages The Philosophical Synthesis of MarxNot very long ago it was extremely fashionable among official men oflearning to say that Marx had really produced nothing new in thephilosophical sphere. Such a well-known philosopher as Wilhelm Wundt inhis Introduction to Philosophy wrote "This lack of clarity in itsmetaphysical premises (i.e. of Marxism. N.B.) has a comprehensiblebasis in the fact that practical questions alone interest