This is done by a procedure called refluxing. Refluxing is the process of heating a product to the boiling point and re-condensing the vapor continuously. The procedure halogenation is the addition of a halogen to a π bond forming a halo alkane. In this synthetic reaction bromine was used in the process called bromination. The bromine is acting first like an electrophile, and then after bromine has broken the π bond, a carbocation has formed, and a bromide ion has been created, the bromide ion then acts as the nucleophile and forms a bond with the carbocation.
Electron donating substituents attached to the diene, accelerate the reaction as do electron withdrawing groups on the dieneophile . The Alcohol acts as the diene and the anhydride as the dieneophile. The Diels–Alder reaction is a highly stereoselective reaction. In order for the reaction to occur the diene must be in the s-cis formation .The trans, trans-2,4-Hexadiene-1-ol can adopt the cis formation by rotating around a sigma bond while still maintaining Trans stereochemistry . The position of the diene to the dieneophile in the transition state determines the
| The SN2 reaction-Preparation of n-butyl bromide | | | | | Name: Aasefa Shaikh Date: Mon Sept. 26, 2011 Subject: Chem 3000- Organic Professor: Arturo Orellana TA: George Achonduh Name: Aasefa Shaikh Date: Mon Sept. 26, 2011 Subject: Chem 3000- Organic Professor: Arturo Orellana TA: George Achonduh Abstract The formation of n-butyl bromide from 1-butanol and sodium bromide was observed under SN2 conditions. It was observed that the bromine anion, a strong nucleophile, was able to attack the protonated alcohol and displace water, which serves as a better leaving group than the hydroxide ion. The primary structure of 1- butanol allowed the bromide anion to a backside attack which led to a transition state, the rate determining step, followed by an inversion of the product, n-butyl bromide. The mass of the product obtained was 6.92 grams, giving only 33.7% percent yield. Introduction Nucelophilic substitutions are chemical reactions in which an electron rich nucleophile attacks the electron poor electrophile1.
CH 341 – Laboratory Techniques in Inorganic Chemistry Experiment 1: Identification of Stereochemical (Geometrical) Isomers of [Mo(CO)4(L)2] by Infra-Red Spectroscopy Abstract Purpose of this experiment is to prepareone isomer of molybdenum carbonyl complex, [Mo(CO)4(pip)2], and both possible isomers of [Mo(CO)4(PPH3)2] using convenient literature method. Examining the CO stretching region of the IR spectra, the isomers will be identified. Introduction Metal carbonyl considers as one of the most important class of organometallic compounds and many studies of their chemistry and their bonding characteristics has been done (2). Metal carbonyls were first considered as laboratory interests, but soon achieved huge industrial applications (6). The technique of infrared spectroscopy, in both the solid and solution phases, has proved to be of very useful in these studies.
Experiment: Cyclohexanone from Cyclohexanol aq Abstract: The primary objective of this experiment was to create cyclohexene from the dehydration of cyclohexanol with phosphoric acid. Through the use of simple distillation it was possible to separate the solution. The Agilent 7890A Gas Chromatography System was used to determine the purity of the distillate which verified the success of the separation. Introduction: Alkenes can be prepared by from alcohols by an acid catalyzed dehydration reaction. In the experiment a secondary alcohol (cyclohexanol) is heated with acid (phosphoric acid).
However, the alcohol remains fairly constant in the form of glycerol or in other words propane -1,2,3- triol. This form of alcohol contains a hydroxyl allowing longer chains to form of carbon. 7. A common commercial use for esters is in the perfume industry where a synthetic scent is created within labs through the process of esterfication. For example, Benzyl Acetate is one form of an ester that can be used as to create a perfume
Nitration of Methylbenzoate Aim: The aim of the experiment is to successfully perform the nitration of Methylbenzoate by the recrystalisation method and in doing so obtaining a melting point and the infra-red spectra graph of the product. Introduction: Methylbenzoate is an aromatic compound and it is structurally related to Benzene. It has an electron rich aromatic ring which makes it vulnerable to electrophiles this in turn making them react. A common electrophile is used in this reaction, which is the NO2+ nitronium ion. It is produced by reacting nitric acid and sulphuric acid simultaneously.
The net reaction is: This reaction has been studied extensively and occurs for a wide variety of ketones. In general, the halogenations of a ketone can be represented as follow: The main evidence for any mechanism is provided by kinetic studies to determine an experimental rate law. Following the rate law of chemical kinetics, the differential rate equation for the reaction could be written as follow: Where k = rate constant; a, b,c are the orders of the reaction of S, I3-, and H+ respectively. I3- ion is the only coloured species in the reaction mixture, a spectrophotometer can is used to measure the change in its concentration, by applying the Beer-Lambert Law Where A= absorbance, ε= molar absorption coefficient, [I3-]= concentration and /= optical path length, that is, the distance travelled by the light through the solution. The ideal wavelength for the measurement of
Most of the systems vary to include ratios of chloroform, methanol and water. triethylamine, ethanol, hexane, and isopropanol are also common solvents in the mobile phase. Phospholipids migrate to the stationary phase a certain distance on the basis of the composition and affinity for the mobile phase. Identification is based on the delay (Rf), wherein the ratio of the distance moved by the analyte (i.e., the phospholipids) from the origin of the distance moved by the flowing solvent from the origin. Each of the analyte will have its own Rf value under certain circumstances.
Conclusion: Experiment, was successful to purified benzoic acid with the technique of recrystallization and extraction. In the technique of recrystallization, the percentage recovery yield was determined to be 22.67% and the melting point 107-117 Celsius (See page 10 on lab note). For the technique of extraction, it had been determined to be . It concluded that the extraction was the best technique to purify the benzoic acid since it less time consume and achieve more of the mass. Recrystallization method was achieved by the sample that contained benzoic acid, sodium chloride and p-nitroaniline.