INTRODUCTION Hydrazones1-3 were reported to possess various biological activities. In the present communication we report the synthesis of new phenyl hydrazones. These hydrazones were synthesized by using different aromatic aldehydes which react with phenyl hydrazine in presence of alkali to undergo condensation by removal of one mole of water molecule. It is the simplest reaction to form reactive phenyl hydrazones. The synthesized compounds after purification were characterized by spectral methods viz.
Pankti Gandhi 9/26/14 Separation of Liquids by Simple Distillation and Analysis by Gas Chromatography Methods/Background: The purpose of this experiment was to separate two volatile components from a mixture due to the different chemical properties of each compound. The mixture used in this experiment was ethyl acetate (EtOAc) and butyl acetate (BuOAc). The mixture containing two liquids will be separated by a separation procedure known as distillation. This method relies on each compound having a distinct and separate boiling point.
By applying the general solubility rules listed below, the precipitate or lack of were then able to be analyzed to determine each substances identity after mixing on a spot plate. Given that specific compounds react differently when mixed with another substance, the precipitate, pH, and chemical equation of the reaction itself was utilized in determining the substance. Procedures such as the one conducted in this experiment are especially useful in determining which chemical is which, if it is unable to be deduced through pH, smell, or
To begin benzoic acid has a melting point of 121-125C. The melting point of recovered benzoic acid was 109-115C. There is a noticeable broaden and depression of the melting point which points to impurities. For the benzoic acid in particular the impurity could have been the ice cold water. To combat this next time, essential time should be allotted for the suction filtration to the component to dry and also a heating lamp could have been used to rid the benzoic acid of water. Next, benzocaine has a melting point of 89-92C. The melting point of recovered benzocaine was 77-99C. This melting point was significantly depressed and the range was dramatically broadened. A way to ride the component of impurities, once could suction filtrate the component for a longer amount of time or use a heat lamp to fully dry the component. Lastly, fluorenone has a melting point of 80- 83C, but the measured melting point of the component in the 1:1:1 mixture was 80-81 C. This reading is fairly close to the literature value, however to ensure a more accurate reading for the isolation of fluorenone, the sample could be heated longer or a sufficient amount of a drying agent would be
The goal of the lab was to separate a neutral compound and an acid from an unknown mixture. The DCM (Dichloromethane) was added to create the organic layer. Both the neutral compound and acid were insoluble in water so aqueous NaOH was added. The acid would be deprotonated into an ion, which is soluble in water. Using the separatory funnel, the organic layer was separated from the aqueous layer. HCl was added so that the ion would protonate back into the acid and precipitate out of solution. Vacuum filtration via Buchner funnel was used to separate the acid (crystals) from the salt, NaCl. Na2SO4 was the drying agent used to remove any residual water from the organic layer. Gravity filtration helped separate the drying agent from the organic layer containing the neutral compound. The organic layer (DCM solvent) was boiled in order to separate the solvent from the neutral compound, which was in the form of crystals. Ethanol was heated up and added to the crystals of the neutral molecule which allowed the removal of impurities. The solution was placed in a hot water bath and the crystals of the neutral molecule precipitated out. The cool temperature helped crystallize the neutral compound into crystals. Finally, the neutral compound crystals were separated via vacuum filtration using a Buchner funnel. The acid and neutral compound and massed via an analytical balance so that the percent recovery can be calculated. Melting point (Mel-temp) was used to determine the
As the reagents were heated, a strong banana odor was present, and was especially strong during extraction. The condensed product was then cooled to lower the temperature, which allows for the C-O and O-H bonds in the products to form. Sodium bicarbonate was added to the acetic acid to form sodium acetate and carbonic acid, since the acetic acid was highly water soluble. The carbonic acid was then spontaneously broken into water and carbon dioxide molecules. The sodium acetate was extracted after each time the sodium bicarbonate was added for a total of four times.
The same technique was used for the determination of the unknown; however, the solution used for each method was slightly different. Furthermore, the mobile phase in each method was of different concentration with the addition of ethylacetate in Solvent system A.
The melting point was determined for both the crude and purified aspirin samples. The crude aspirin sample produced a melting range of 90˚-101˚celsius and the purified aspirin sample produced a melting of 117˚-132˚celsius. The melting point of the crude sample was determined to be 101˚C and the melting point of the purified sample was determined to be 132˚C. The
Extraction is the process of selectively removing a compound of interest from a mixture using a solvent1. There is liquid-liquid extraction, which is based on the varying solubilities of different solutes in immiscible solvents2. There is also acid-base extraction, which is what was performed in this experiment. An acid-base extraction is a type of liquid-liquid extraction and is used to separate organic compounds from each other based on their acid-base properties3. The goal of this experiment was to extract and identify three unknown components from a mixture using extraction techniques based on acid-base properties, confirm the identities with a mixed melting point analysis, and compare the percent yields of each component to the expected
The three components of the unknown mixture were identified as Benzoic Acid, m-nitroaniline, and Naphthalene, as seen in Table 1. The melting point of the acidic component was 121.9℃-123.8℃ while the literature melting point of the suspected acid, Benzoic acid, is 121℃-122℃. The melting point of the basic component was 112.9℃-117.2℃ while the literature melting point for the suspected base m-nitroaniline was 111℃-114℃. The melting point for the neutral component was 77.9℃-82.8℃ while the literature melting point of the suspected compound Naphthalene is 79℃-82℃. The mixed melting point technique analytically confirmed the three identities of the components in the mixture because the melting point ranges for each component were extremely similar to the literature melting points of the suspected compounds.
The 4-nitrobenzoic acid product had a percent yield of 48.89%, showing a very high yield out of 50%. The melting point range was from 236-238°C, whereas the literature value is 237-240°C. The melting point of the product was very close to the literature value and also had a narrow range, indicating a pure product and therefore deeming recrystallization unnecessary. However, if the acid need to be purified, methanol would be used as the recrystallizing solvent.
The solubility test was done first to help eliminate some of the possible solutions. When the solubility test was conducted, 5.0 mL of water and 0.5 grams of the unknown compound was used. The 0.5 grams of the unknown compound
A couple of mixtures of unidentified organic compounds (a mixture of two liquids and another mixture of two solid compounds) were obtained, and the compounds of each mixture were then separated, isolated, and purified. The compounds of the liquid-liquid mixture were isolated by simple distillation, and the compounds in the mixture of solids were extracted by liquid-liquid extraction, and later purified through recrystallization. Physical properties –such as boiling points, melting points, and densities- were used to identify each isolated compound. After analysis, the first liquid was identified by a boiling range of 81.0°C-81.3°C and a density of 0.7882g/mL, and the second liquid was identified by a boiling range of 91.7°C-91.9°C and a density of 0.8578 g/mL. The crude solid products were purified and recrystallized, providing a white crystalline solid (MP = 35.2-37.8 °C) in 46.9% yield, and a white powdery solid (MP = 121.9 – 122.1 °C) in 2.40% yield.
The melting range for each substance occurred very quickly, only lasting for about 2-4seconds. There was not distinct color change between any of the substances that were used. The substance that had the quickest starting melting point was the 50/50 substance with a melting rate between 99.2°C and 129.8°C. The 50/50 substance also had the longest meting range of about 20 seconds when the other substances had quicker melting rates of about 2-4 seconds. When the unknown substance was placed in the DigiMelt the first time, it had a melting range from 115.2°C to 119.0°C, but when it was tested again in part two and compared to acetanilide, they both had a range from 114.4°C to 118.1°C. This determined that the unknown substance being tested was acetanilide. The melting point of acetanilide obtained from this experiment is similar to the melting point found on the website, PubChem, with a melting point of 114.3°C(Acetanilide, 2015). This shows that the results collected from this experiment are accurate and that the unknown substance tested was acetanilide.Determining the melting point of a substance is an