nucleoside followed by chemoselective O-deacylation (Schaller et al., 1963 ; Rigoli et al., 2009). (2) “Transient” protection approach (Ti et al., 1982) has been widely used. In this procedure, the nucleoside is persilylated using a silylating agent, and the acyl function is installed on the amino group using the corresponding acid chloride or acid anhydride. (3) Some acyl functions such as benzoyl, α-phenylcinnamoyl, and naphthaloyl are directly incorporated on the nucleobase using the corresponding anhydride (Watanabe and Fox, 1966; Bhat et al., 1989). Zhu et al. (2003) reported an improved synthesis of N-benzoylated nucleosides by reducing the amounts of chlorotrimethylsilane (TMSCl) and benzoyl chloride to nearly equivalent quantities. The major advantage of this method is the easier work-up and higher yields. The original method by Ti et al. (1982) was further simplified by eliminating the addition of ammonium hydroxide. (4) The exocyclic amino group of cytidine and deoxycytidine were directly acylated using activated esters (Igolen and Morin, 1980), acid chlorides (Mishra and Misra, 1986, and references therein), or alkyloxycarbonylbenzotriazoles (Himmelsbach et al., 1984). (5) Site-selective incorporation and removal of N-acyl protecting groups have also been achieved by enzymatic methods (Prasad and Wengel, 1996). (6) Selective acylation of nucleosides has also been carried out by N-acyltetrazole (Bhat et al., 1998) and carboxylic acids activated in situ with…
In this experiment, two cations in an unknown solution were found using qualitative analysis. For Part A, the solution was to contain either silver or lead, while in Part B, the solution that was set on the side form Part A was identified to contain either calcium or barium. Part C explored a different method through the use of cation flame tests to observe colored flames from six metal chloride solutions.
In Part A, the initial step was to add HCl to the unknown sample. This was necessary…
Other groups were assigned with glucose and sucrose. Diluting 1 M of sodium chloride with water made six solutions. The six solutions ranging from 0M to 1M were prepared. These 6 solutions composed of 50 mL of solutions with different concentration of NaCl. The uses of concentrations of NaCl were 0M, 0.2M, 0.4M, 0.6M, 0.8M, and 1M. Then 6 equally sized and shaped cylinders of potato were obtained and weighed initially. Then these 6 potatoes were put inside of the sodium chloride solutions. After…
experiment was to determine the percent of chlorine in an unknown soluble salt through using gravimetric techniques. The unknown salt was dissolved in water and the chloride ions were precipitated using silver nitrate which produced silver chloride. The silver chloride was then separated by filtration techniques and through this the amount of chlorine in the original salt was able to be calculated. It is expected that the chlorine percent will be around 55.95% because that is the accepted value…
Phenols Degradation by Fenton Reaction in the Presence of Chlorides and Sulfates
Siedlecka et al. (2005) also studied a series of phenol compounds present in wastewater. These compounds, as mentioned above, are widely used therefore are commonly found in wastewater derived from different industries such as petrochemical, food or resin manufactured.
Since common biological treatment for these kinds of compounds is not feasible, is important to develop new technologies to treat these…
If the substance clumps at the bottom, continue to stir until the mixture is dissolved completely.
Take a clean volumetric pipette and set up five test tubes.
Using the pipette, portion out 0.1 ml of the unknown solution and place it into each test tube. This will evenly divide the solutions for testing.
Fig. 1 The purpose of the ph test
is to determine whether the solution is acidic or basic.
Next, taking a ph strip, dip the end of the strip into the solution to gauge the ph.…
How to choose the best lash extension training course for you?
Description: the artificial eye lashes are created in order to increase the beauty of a woman’s eye. In order to get trained in this, you can join the best eye lash extension training courses. Know how to select one.
There can be a plethora of choices in eye lash extension training course, but in order to choose the best one from there, you need to consider your objective and requirements properly. There are various sources from…
What factor(s) affect the rate of reaction?
Problem: What effects does temperature have on the rate of reaction?
Purpose: The aim of this investigation is to investigate how changing the temperature of sodium thiosulphate affects the rate of reaction in a chemical reaction. In order to complete this practical the temperature will be changed three times and the rate of reaction will be measured each time.
Variables: Independent: -the temperature of the sodium thiosulphate.
0.2 M nitric acid, (HN03); storage code: White
Store bases in a labeled, locked, corrosion resistant cabinet.
Lab-grade sodium hydroxide pellets, (NaOH);storage code: White
Store flammables in a labeled, locked, flammable liquid storage cabinet.
70% ethyl alcohol, (C2H6O or CH3CH2OH ); storage code: Red
Denatured alcohol, (90% ethanol/10%methanol content ); storage code: Red
Store water sensitive chemicals in a labeled, locked, water-tight cabinet in a cool and dry location segregated…
Table 2. Recorded data of Physical and chemical properties of Wakefield Pond.
Figure 3. Graph of temprature vs Depth in each lake.
Figure 4. Graph of oxygen concentration vs Depth in each lake.
Figure 5. Graph of light vs Depth in each lake.
Figure 7. Sketches of plankton and relative aboundace from all two lakes
Figure 8. Sketches of plamkton and relative aboundance from all two lakes.
Figure 6. Fish in Wakefield Pond variety and numbers.