Purification of Product of Rxn Between MTT and CNP, and Large-Scale Reaction Setup
Note that MTT refers to 5-(methylthio)-1,3,4-thiadiazole-2-thiol, and that CNP refers to 2-chloro-3-nitropyridine. Structures shown here
Goals:
- To purify the products of my second reaction (Ross carried it out with the modified procedure).
- To set up a large-scale version of the previous small-scale reaction. Target compound must be synthesized and purified by Wednesday (10/07/15)
Procedure for purification:
- The product was shown to be slightly soluble in ethyl acetate (which is more polar than dichloromethane). The insoluble impurity could be the result of residual triethylamine. A "dirty column" was run in an attempt to remove the impurity.
- The column was a Büchner funnel containing powdered silica, which sat in a vacuum flask.
- The powdered silica was then made into a slurry with hexane.
- The compound, once redissolved in methanol, was run through the column. It was hoped that the triethylamine would remain in the silica.
- After the fraction collected with ethyl acetate was obtained, another flask was used to collect a methanol fraction.
- Mass spectrometry was used to examine the two fractions. The result is shown below:
Procedure for large-scale rxn:
- Calculations:
- Start with mass of CNP and get moles of CNP: [math]\displaystyle{ \frac{250mg}{1}|\frac{1g}{1000mg}|\frac{1mol}{158.54g}=0.00158mol }[/math]
- Get mass of MTT using moles of CNP (use 5% extra MTT since it is less valuable): [math]\displaystyle{ \frac{Xg}{1}|\frac{1mol}{164.27g}=1.05*0.00158mol=0.001659mol }[/math]
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