Unknown Grignard Reagent

Bromination is the process where an alkene is halogenated with bromine. The purpose of this experiment was bromination of stilbene to stilbene dibromide. The element bromine is toxic and requires maximum care when used. Bromine was generated in the reaction mixture by using a green method. Less hazardous reagents were used to do so. This can be seen by the chemical reaction 2HBr+H_2 O_2→〖Br〗_2+2H_2 O. Hydrogen peroxide is used to oxidize HBr to 〖Br〗_2. By adding hydrogen peroxide this can make working with bromine less dangerous. This experiment is a greener approach to the bromination process because ethanol was used as a solvent. Ethanol is nontoxic making the experiment less harmful.

The triphenymethanol product was a very fine white powder that had a slight yellow tint to it. The experimental melting point was calculated to be 159.0-159.6°C, which is very accurate compared to the actual melting range of 160-163°C. The percent yield came out to be 26.89%, which is most likely low due to using heating plates to heat the end reaction instead of the recommended steam baths.

The purpose of this experiment was to synthesize a Grignard reagent with 1-bromobutane and homogenized magnesium in anhydrous diethyl ether. This solution was refluxed in a flask connected to condenser and drying tube. As seen in the mechanism, maintaining a dry condition is important to avoid the Grignard reagent from attacking water, which will result in loss of the bromine. It is important to reduce the amount of moisture and water vapors to avoid destroying the Grignard reagent, which is essential to the synthesis of 2-methylhexanol. Hence, a calcium chloride and cotton were filled inside a drying tube. The condenser was wrapped with parafilm and a paper towel to avoid moistures from entering. The reagent will act as nucleophilic addition to acetone and work up with hydrochloride acid to synthesize 2-methylhexanol.

The objective of the experiment is to synthesis cis-Norbornene-5,6-endo-Dicarboxylic anhydride in a Diels-alder reaction. The chemicals used are Maleic anhydride and Cyclopentadiene. In this experiment, the melting point and of cis-Norbornene-5,6-endo-Dicarboxylic anhydride is determine. Also, the percent yield.

The reaction of the product with potassium ferricyanide produced a blue-green glow. This identified the product as luminol.

Boron is an element of the periodic table belonging to the group 13. It is the only non metal present in its group. Boron has three valence electrons. It is capable of forming covalent bonds between atoms of similar nature to form polyhedral clusters. Boron has 2 stable isotopes in nature. i.e.11B (80.1%) and 10B (19.9%). Boron exists in bound state.

The Diels-Alder reaction has been an area of great research interest with regards to enhancing enantioselectivity in the reaction by use of various catalysts and reaction conditions.

All the data used for analysis of the neutral compound was received from Andrew ______, since there was not enough sample left to perform MP analysis after the recrystalization step. Since the ranges for these melting points are larger than the ranges observed for the recrystalization product, it can be inferred that these samples contained impurities, and also possibly traces of ethyl acetate or water, depending on the solvent they were in. These melting points can also be used to make a rough guess about the identities of these compounds, as seen later in this report. According to the MSDS pages for salicylic acid, 4-nitroaniline, and p were 159, 148.5, and 101 respectively. The melting points for the acidic and neutral compounds were hence too low, and the melting point for the basic compound was too high. The errors in the acidic and neutral compounds can be explained by impurities in the crude product, along with the presence of the solvents, ethyl acetate and water, which disturbed the stability of the compounds, and led to lower melting points over a larger range. The abnormally high melting point of the base may have been observed due to improper separation of the acid and base solutions in the separation funnel. Some of the acidic compound may have entered the basic solution and reacted with the base to form a high melting point salt, making the melting point of the base appear abnormally high. The Mel-Temp was also turned on a high setting accidentally, so it is possible that the temperature rose too quickly to get a good reading of the melting

The Wittig reaction is valuable reaction. It has unique properties that allows for a carbon=carbon double bond to form from where a C=O double bond used to be located. Creating additional C=C double bonds is valuable due to its use in synthesis. The Wittig reaction will allow the synthesis of Stilbene (E and Z) from a Benzaldehyde (Ketcha, 141).

In this lab, three unknown compounds were separated from a mixture and identified by melting point. Unknown mixture #124 has components of acid, base and neutral compound. The compounds were identified by melting point and matched up with the known melting points from a given list. In order to identify the compound it was important to separate by dissolving the mixture in an organic solvent which was not soluble in water, and then extracting the solution first with HCl, and then dilute sodium hydroxide solution. From the separation mixture, the aqueous layer were obtained and labeled as TT-1 (base), TT-2(acid) and TT-3 (neutral) in three different test tubes for later recovery. The procedure steps were followed as indicated which led to the correct identification of the tree compounds. The experimental melting points of acid and base were fairly close to the theoretical melting point. However the melting points of neutral were not as close due to some impurities in the compound. Determination of melting point for sample #124 acid and base were accurate due to no presence of impurities. The base was correctly identified as 5-chloro-2- methoxyaniline with a

A way to determine the molar mass of an unknown substance is to use other properties of that substance and solve for desired information. In this experiment, a colligative property, like the freezing point of an aqueous solution of the unknown substance, was used to find the molar mass of the substance. With the molar mass discovered, the identity of the substance was found.

The objective of this lab was to determine the activating strengths of the directing groups in aniline, phenol, acetanilide and anisole by using melting point to identify the products of their electrophilic aromatic bromination reactions with pyridinium tribromide in glacial acetic acid.

The aim of this experiment was to create Butyl Ethanoate by the process of reflux esterification using 1-Butanol (, 16mL) and Ethanoic Acid (17.4M, 10mL) as raw materials. A catalyst sulphuric acid (18.0M, 2.0mL) was used to offer an alternate reaction pathway and forcing the equilibrium to shift to the right as it is a dehydrating agent result in a greater yield of ester. All reactants were heated under reflux for a total time of 45 minutes, boiling chips were added into the pear shaped flask to encourage even boiling and prevents the occurrence of superheating.

1,3-butadiene is formed from 3-sulfolene by thermal decomposition. It is important to work with very concentrated solutions of two different reagents because they help create the bonds in the six-membered ring. The reagent that was taken in excess was xylene. Xylene, a non-polar solvent, can be used for this reaction because it will not react with the solvents. Xylene should be dried because it will be removed from the product. A drying tube with calcium chloride was used for the reaction during the set up because it will remove and catch specific compounds leaving the reaction or being produced from the reaction. The purification method is by using adding petroleum ether to produce crystals and then vacuum filtration to remove the crystals from the solution. The melting point for 4-cyclohexene-cis-1,2-dicarboxylic anhydride as a pure compound is measured at approximately 97-103ºC. The measured melting point from the experiment is approximately 70-80ºC. The difference between the melting point temperatures can have been caused by excess xylene or water in the

Monomeric silicon chemicals are known as silanes and any chemical that contains at least one carbon-silicon bond is known as an organosilane. Generally, organosilanes contain three key elements beside silicon; X represents for an organic moiety that is non-hydrolysable which can be either reactive or non-reactive depending on its type. OR\ is a hydrolysable group such as alkoxy or an acetoxy is known to be unstable when present with hydroxyl groups. Finally, R is a space moiety, which can be aryl or alkyl chain. Typically, due to the dual reactivity of organosilane, both alkoxy group (OR\) and non-hydrolysable organic moiety (X), it is used to couple inorganic or organic substrates such as minerals, metals or cellulose and polymeric matrices such as rubber, thermoplastic or thermosets to improve its physical properties. The applications include adhesion promoter, dispersing/hydrophobing agent and crosslinking agent.