* In the above RB, a calculated amount of 1.2 equivalent amount of PTSH was added during continous stirring. * To the RB a condenser was attached and it was put on refluxing for a time period of 18 hours at a temperature of 80 degrees in an oil bath. * Post refluxing, the condenser was removed and it was left undisturbed for 1 day and then cooled to a temperature of -20 degrees by keeping in the freezer for setting of hydrazone crystals. * Once the crystals were formed, the supernatant was decanted and the crystals were transferred to a beaker where they were washed with cold methanol and then dried. * These dried hydrazone crystals were used in the subsequent steps.
The mixture was finally made upto 5 mL with distilled water and placed in hot water bath at 95ºC for 1 h. After cooling, 1 mL of distilled water and 5 mL of the mixture of n-butanol and pyridine (15:1, v/v) was added. The mixture was vortexed and after centrifugation at 4000 rpm for 10 minutes, the absorbance of the organic layer (upper layer) was measured in UV-Vis spectrophotometer (Shimatzu) at 532 nm against blank using distilled water. TBA when allowed to react with MDA aerobically formed a colored complex [MDA-(TBA) 2 complex] which was measured with spectrophotometer. MDA concentration (measured as TBARS) was calculated as
5-aminotetrazole monohydrate: In a 250 ml round-bottom flask equipped with a condenser for refluxing (90 °C) and a magnetic stirring bar, 5.00 g (5.95 mmol) dicyandiamide (three times crystallized), 7.47 g (11.9 mmol) sodium azide and 11.00 g (17.8 mmol) boric acid and 100 ml of water is added and allowed to reflux for 24 hours, after the completion of the reaction, until the solution pH to about 2 to 3 as hydrochloric acid 37% is added (about 12 ml) Then the reaction mixture was cooled in a refrigerator for 18 hours and the white crystals formed. The mixture was filtered and washed three times with 10 ml of water and and dried in 60 °C for 5 hours and finally 45.8 g of product by it will be obtained. 5-Aminotetrazol monohydrate: Yield:,
In this experiment, racemic 2-methylcyclohexanone was reduced using sodium borohydride as a nucleophile to give a diastereomeric mixture of cis and trans secondary alcohols. The products were analyzed for purity using IR spectroscopy and gas chromatography. 1.2 g of 2-methylcyclohexanone and 10 mL of methanol were combined in a flask and cooled in an ice bath. Two 100 mg portions of sodium borohydride were added to the flask and stirred. 5 mL of 3M sodium hydroxide, 5 mL of de-ionized water, and 15 mL of hexane were added to the reaction flask and stirred.
The purpose of this experiment was to perform a Wittig reaction using two different methods: In method I, 250 mg aldehyde was mixed with 785 mg phosphonium salt in 5 M NaOH solvent. This mixture was stirred for thirty minutes and filter by vacuum filtration for the product. In method 2, 250 mg of aldehyde, 785 mg, benzyltriphenylphosphonium chloride, and 380 mg potassium phosphate tribasic were homogenize with a pestle and mortar. Vacuum filtration was also used in this method to attain the product. The products in both methods were used for recrystallization and TLC.
We then slowly added 25ml of chilled deionised water to the filtrate to initiate crystallization by using a measuring cylinder and a dropping pipette, once we had done this we left it for about 10 minutes to allow crystallization at room temperature. We then weighed a filter paper which we will use later in the experiment. We then collected the crystallized acetylsalicylic acid by vacuum filtration in a Buchner funnel and washed the product with a little ice-cold water. We then pre-weighed a clean, empty watch glass and labelled it with our initials and the date, we did this do we could easily identify that it was ours when we go to weigh it with the crystals on. We
Then an estimated (by trial and error) 1-3 grams of hydrated copper sulfate was added to a crucible with the lid on top. The total mass of the hydrated copper sulfate was recorded by subtracting the total mass of the crucible, lid, and sample from the mass of the crucible and lid (described in table 1.3). By attaching the wire triangle to the ring, the crucible was able to sit securely while having the bunsen burner underneath. Lighting the burner once again, each substance was heated for several minutes until estimated that the compound had changed color. Once a prevalent color change had been observed at approximately 4 minutes (blue green color) the crucible was set on the counter using the tongs to cool for approximately 5 minutes.
Whereas, 3T and 4T turned yellow, which indicated that the hydrolysis happened. It is a evidence of the dye molecules in the BAPNA has been cleaved form the amino acid when trypsin and BAPNA were combined together. However, 5T had interesting result when trypsin and BAPNA solution was placed in the ice box for an hour. Even though, it is a
Two drops of iodine- potassium was then added to the mixture. The procedure was repeated with the rest of the samples and isopropyl with varying drops of sodium hydroxide. Eight drops of sodium hydroxide was added to formaldehyde, 9 drops to cyclohexanone, 15 drops to benzaldehyde, and 7 drops to isopropyl. It was observed that both cyclohexanone and benzaldehyde formed a yellow layer that lasted only for a few seconds before disappearing completely while the formaldehyde mixture produce a yellow precipitate. Both acetone and isopropyl mixtures were heated since no precipitate was observed.
A sample of fish oil (50 mg) was transferred into screw-cap vial. 2 ml benzene and 10 ml sulfuric acid (1%) in absolute methanol were added. The vial was covered under a stream of nitrogen before heating in an oven 90 °C for 90 minutes. Ten ml of distilled water were added to the cooled vial and the methyl esters in each vial were extracted with 5 ml of petroleum ether for three times. The three petroleum ether extracts were combined and concentrate to its minimum volume by using a stream of nitrogen.
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.