Results and Discussion Synthesis of Compound 3. Scheme 1: Synthesis of Compound 3. To synthesize compound 3, an approach involving treating triptolide with dimethyl sulfide and benzoyl peroxide in acetonitirile was used (Scheme 1). This approach resulted in the formation of compound 4 with a 51% yield and in triptonide (5) with a 46% yield. Compound 4 was then used to create the intermediate compound 6 using an N-iodosucciminide-mediated (NIS) nucleophilic displacement with dibenzyl phosphate in dichloromethane and THF exposed to 4 Å molecular sieves. This method resulted in a yield of 91% of compound 6. A sequence of extractions used to purify compound 6 further, which is described in the Materials and Methods section of this paper. This procedure allows for the production of compound 6 to be scaled up and well as obtain efficient …show more content…
It is important that the phosphate prodrug to be catalyzed by alkaline phosphatase to turn into the parent drug within the body. Alkaline phosphatases are found throughout the body, mainly in plasma membranes. To confirm that the phosphonoxymethyl prodrug would be broken down in the face of alkaline phosphatase a glycine buffer at pH 9.8 and bovine alkaline phosphatase was used. It was observed that the phosphate group of 3 was released when exposed to alkaline phosphatase and replaced with a hydroxymethyl derivative (7). Due to the fact that the hydroxymethyl derivative is highly unstable, it was quickly converted into triptolide, but also released milligram amounts of formaldehyde. The reaction is shown in Scheme 2. Although, the release of formaldehyde may cause concern for some people, it is actually a very small amount when compared to the 31-59 g that the body’s metabolism produces every day. The formaldehyde also had a short half-life of 1.5 minutes, so exposure to this formaldehyde would be very short because it would be quickly converted into formic acid within
Atoms are the basic units of matter and all life is based on them. Life on earth is based on the element carbon. It is a highly versatile atom able to form four covalent bonds with itself or other atoms such as hydrogen and water. Atoms combine to form molecules and those that are carbon based are referred to as organic molecules. Organic molecules occur in four different types in living cells; carbohydrates, lipids, proteins and nucleic acids. They are also known as hydrocarbons due to the presence of both hydrogen and carbon. Carbohydrates are made up of carbon, hydrogen and oxygen in the ratio 1:2:1. They are important sources of energy and are classified in three main groups; monosaccharides, disaccharides and polysaccharides.
A chemical reaction is when substances (reactants) change into other substances (products). The five general types of chemical reactions are synthesis (also known as direct combination), decomposition, single replacement (also known as single displacement), double replacement (also known as double displacement), and combustion. In this lab, the five general types of chemical reactions were conducted and observations were taken before, during, and after the reaction. Then the reactants and observations were used to determine the products to form a balanced chemical equation. The purpose of this lab was to learn and answer the question: How can observations be used to determine the identity of substances produced in a chemical reaction?
Salicylic acid was esterfied using acetic acid and sulfuric acid acting as a catalyst to produce acetylsalicylic acid and acetic acid. The phenol group that will attack the carbonyl carbon of the acetic anhydride is the –OH group that is directly attached to the benzene since it is more basic than the –OH group attached to the carbonyl group. This method of forming acetylsalicylic acid is an esterification reaction. Since this esterification reaction is not spontaneous, sulfuric acid was used as a catalyst to initiate the reaction. Sulfuric acid serves as the acid catalyst since its conjugate base is a strong deprotonating group that is necessary in order for this reaction to be reversible. The need for the strong conjugate base is the reason why other strong acids such as HCl is not used since its conjugate base Cl- is very weak compared to HSO3-. After the reaction was complete some unreacted acetic anhydride and salicylic acid was still be present in
Being able to identify an unknown compound is incredibly important as it would allow chemists to synthesize compounds in various reactions and identify the products. Although balancing an equation is always possible, full and complete reactions based on a chemical equation are not possible in practice, and as such, being able to identify what was actually created would be important. Additionally, it would be important to
This is done through a change in temperature. Over time, two objects that are in direct contact will
In this laboratory experiment a synthesis was performed through several separate steps. The purpose of the experiment was to synthesize tetraphenylcyclopentadienone from benzaldehyde and to run reactions on carbonyl containing compounds. There was a total of three steps that led up to the synthesis of the final product, tetraphenylcyclopentadienone. The first step of the experiment was the condensation of benzaldehyde to yield benzoin. Thiamine catalyst along with water and ethanol were added to the benzaldehyde, then NaOH was added until the solution turned yellow. After recrystallization, the product was benzoin. Step two was the oxidation of benzoin to benzil.
Substance one was determined to be iron because it was magnetic, and the its melting point was 1535℃, its boiling point was 3000℃, and its density was 1870 g/L. Substance 2 was determined to be wood, because it was lightweight and grainy and a wooden color. It also floated, meaning it had a density less than water, like wood. Substance 3 was determined to be sand, because it was small rocks, which is sand, and had a melting point of 1610℃, a boiling point of 2230℃, and a density of 2650 g/L. Substance 4 was determined to be salt, because it was made of small, white grains, and conducted electricity. It had a melting point of 801℃, a boiling point of 1413℃, and a density of 2170 g/L. In this lab, physical interactions were used to determine
Purpose: The purpose of this experiment was to observe the many physical and chemical properties of copper as it undergoes a series of chemical reactions. Throughout this process, one would also need to acknowledge that even though the law of conservation of matter/mass suggests that one should expect to recover the same amount of copper as one started with, inevitable sources of error alter the results and produce different outcomes. The possible sources of error that led to a gain or loss in copper are demonstrated in the calculation of percent yield (percent yield= (actual yield/theoretical yield) x 100.
First, the solutions and LabQuest was prepped for the experiment. Using graduated cylinders, 100mL of 6M HCl was added to 200mL of deionized water in a 600mL beaker and was stirred to make 300mL of 2M HCl solution. Another solution of 150mL of 2M NaOH was made when 100mL of 3M NaOH was added to 50mL of deionized water in a 400mL beaker and then stirred. LabQuest was plugged into the power outlet, turned on, and attached with a temperature probe into channel 1. Settings for LabQuest were completed when “sensors” then “Data collection” was selected in “Sensor view”, the Mode box was defaulted to “Time based” data collection, “15”s/sample was set in the Interval box, Duration was set to “180s”, and “OK” was clicked to save these settings.
The guiding question of this ADI lab was, “What are the identities of the unknown compounds?” The goal of this lab was to understand the relationships between moles and molar mass to find the identity of unknown compounds. The mole can be used to measure small amounts of a substance or is used to convert from unit to unit using dimensional analysis. One mole is equivalent to the molar mass in grams of that substance. If you start with the moles of an unknown substance, multiply it by a given compound’s molar mass, and then divide it by however many moles are in the compound of your choice, you will get the mass of the compound. With that answer you can then compare with mass of the compound in the bag to determine its identity. We first started
Label three test tubes A - C and place them in a test tube rack. Using a graduated beral-type pipet and add about 2 mL of the cobalt chloride solution to each test tube A - C. Make sure a pipet is used to measure so that all volumes are equal. Place A in an ice bath, B in boiling water, and C should remain a constant temperature. Add HCl to each and observe.
Acetylsalicylic acid, or also known as aspirin is known to be a drug that relives people of pain and is commonly used even today. It is synthesized from salicylic acid and ethanoic anhydride, both of small quantities. Phosphoric acid was used as a catalyst in the synthesis to speed up the process. Esterification is involved and the final product is aspirin with the presence of acetic acid as the byproduct. In order to create the powder form of aspirin, the process of crystallization was conducted and was run through vacuum filtration. After running through the help of an electronic instrument, the result that was achieved in this experiment was met due to
Introduction The different types of reactions include synthesis, decomposition, single replacement, double replacement, and combustion. A synthesis reaction will occur when 2 or more elements combine to form a more complex substance as seen in equation (1).3 A decomposition reaction will occur when a complex substance breaks down into a simpler substance as seen in equation (2).3 When one element replaces another element in a compound it is called a single replacement reaction as seen in equation (3).3 Different atoms in two different compounds trade places during a double replacement reaction in equation (4).3 When a combustion reaction occurs, a hydrocarbon(X) is combined with oxygen to produce carbon dioxide and water shown in equation
To the above solution, n-butylamine (0.90 mL, 0.90 mmol, 1.5 equivalent) dissolved in DMF (5.0 mL) was added drop wise for 15 min with stirring. The reaction mixture is continuous stirred for 24 h at 60 0C, and then it was quenched by the addition of 4 N HCl (20 mL). The mixture was stirred at 600C for 30 min, neutralised with saturated aqueous NaHCO3 and then the aqueous layer was extracted with EtOAc (3 x 50 mL). The combined organic layers were washed with brine, dried over Na2SO4, filtered and concentrated. The residue was purified by column chromatography (SiO2, 5% methanol in chloroform) to afford compound
The reaction scheme is showed in Scheme 1. Briefly, using sulfamic acid as a catalyst, DHPMs1 and DHPMs2 were synthesized by ethanol thermal method. Urea (0.90 g, 15 mmol), acetaldehyde (0.44 g, 10 mmol) / benzaldehyde (1.06 g, 10 mmol), ethyl acetoacetate (1.56 g, 12 mmol) and sulfamic acid (0.8 g, 8 mmol) were dissolved in 10 mL ethanol to form a clear solution, which was settled in a 25 mL teflon-sealed autoclave and maintaining at 80 ºC for 2 h. After cooling, the reaction mixture was cleaned with cold water and 50 % ethanol, and the residue recrystallized from 95 % ethanol to afford the pure product. DHPMs1: Slightly water-soluble white powder; Yield = 1.31 g (71 %); Mp 192 - 193; formula: C9H14N2O3; FW: 198.22; IR (KBr) cm-1:3244, 3118, 2978, 1702, 1654;ESI-MS (m/z): 197.33 (M + H). DHPMs2: Slightly water-soluble white powder; Yield = 2.43 g (93.6 %); Mp 206 - 207; formula: C14H16N2O3; FW: 260.29; IR (KBr) cm-1:3235, 3108, 2975, 1702, 1645;ESI-MS (m/z): 259.18 (M +