Lidocaine Synthesis
A separators funnel is used to separate the organic layer, and the product is rationalized or TTL, GO/MS, and melting point analysis. Pre-l_ABA 1 . What is the limiting reagent in step 1? What is the theoretical yield of amide 1 in figure 3? The amine is the limiting reagent. The theoretical yield is 4. 81 grams Of amide 1 2. What is the theoretical yield Of Leading? Base calculations on 2,6-dimensionality. The theoretical yield of leading is 5. 71 grams. 3. How many molar equivalents of ethyl amine are used in step 2 Roughly 3 molar equivalents of ethyl amine are used in step 2.
Procedure An ice water bath for 100 ml of water was prepared. It was noted that gloves ad to be put on at this time. 3. 0 ml of 2,6-dimensionality in a 10 ml graduated cylinder. Then, a larger cylinder was used to measure out 15 ml of glacial (concentrated) acetic acid. This was poured into a 125 ml Erlenmeyer flask. Both graduated cylinders were rinsed thoroughly with acetone several times. The 2,6-dimensionality was added via a Pasteur pipette to the acetic acid. The graduated cylinder was rinsed with acetone and left to air dry. 2 ml of 2-chlorate’s chloride was measured and poured into the Erlenmeyer flask.
A thermometer was placed to record any temperature change during his process. A large graduated cylinder was used to measure out 25 ml of . 333 M Sodium Acetate directly to the Erlenmeyer flask. The temperature increased from 30 to 32 degrees Celsius. 60 ml of cold water was added directly into the flask. Using a glass stir rod, the mixture was stirred for roughly 10 minutes. The product was isolated using vacuum filtration via a Boucher funnel. A few small portions of cold water was rinsed and pressed dry with another sheet of filter paper.
The 50 ml ROB flask was then weighed (35. Egg). The pressed dry amide was deed to the flask and reweighed toe be 38. 388 grams. 2. 5 ml of delineating, 25 ml of toluene, and boiling chips were added to the flask. The delineating reacted in the graduated cylinder, meaning that it was not properly rinsed. Smoke and a white precipitate formed. Another, clean graduated cylinder was used to measure and pout the delineating. A water- cooled reflux condenser was attached to the round bottomed flask. The water was turned on slowly, and the assembly was lowered into the sand bath.
This was refluxed for 60 minutes, then cooled to room temperature slowly. The suture was transferred into a separators funnel and washed with 150 ml of water in 3 portions. Then, the organic layer extraction took place with 40 ml of 3 M HCI in 2 portions. The aqueous layer was placed into an Erlenmeyer flask. The organic layer was washed with 20 ml of water. This aqueous layer was placed into an Erlenmeyer flask yet again. A thermometer was added and the flask was cooled in an ice bath till the solution reached 10 degrees Celsius.
In small portions, 3 M Sodium Hydroxide was added in portions and in excess of 50 ml During this process, the temperature was supposed to be pet below 20 degrees Celsius. Sodium Hydroxide was added until the pH strip turned dark green. The actual test strip turned lime green, then dark blue with a minimal addition of sodium hydroxide. The compound was later taken for GO and MS analysis. The melting point of the final product was also measured. Data/Calculations TTL of Leading Sample RFC Value Revalue 2,6-dimensionality 0. 51 Co-spot rationalized 0. 35 0. 5 Authentic Leading 0. 8 Melting Point of Sample Melting Point (Celsius) Leading (actual) 68 Leading (sample) 62-64 3. 136 goof amide 1 3. 136/4. 1 *100 = 65. 2 %yield of amide 1 The yield of leading was inconclusive, as most of product was lost due to spill. The product was rationalized, but a significant loss from this spill resulted in an inaccurate percent yield. Conclusion The sample of leading before rationalizations was spilled. Because of this error, a majority Of the product was lost, and very little was left for rationalizations. The spill occurred before the rationalizations, but after the GO/MS sampling.
However, the amide lost significantly more than what was expected in terms of percent yield. The percent yield of the leading cannot be salvaged, but the purity of the product can be determined by the GO/MS sampling. The GO/MS sampling determined a high purity. The Gas Chromatography showed a purity of 97. 89% of Leading. There was a small amount of impurity that was determined to be pentagon. The mass spectrometry confirmed the two compounds by running the sample peak against other known results, and a 97% match was found for leading stud. The impurity peak had a 94% similarity to 2-pentagon.
It is not entirely known why 2-pentagon was found in the sample, but could be due to some are decomposition of leading. The melting point was found to be in a range roughly 6 degrees below the expected resulted. This demonstrates a lack of purity of the compound, but could have also been due to the spill. Whatever product remained still had a small portion of what remained on the ground at the lab station. The purity of the leading was, however, backed up by the GO (as previously explained). The TTL component of the lab further supported the presence of leading.
The RFC values for the co-spot showed a distinct separation Of the leading ample and the 2,6-dimensionality. The Revalue for the sample leading had a slightly higher value and was more non-polar. This could have been due to the tailing which broadened the range of polarity for the compound. The existence of 2-pentagon in solution could have also increased the non- polarity slightly. Post-Lab Questions 2. Ethyl ether could be used as well, as its non-polarity is favored in SON reactions. However, a polar apricot solvent would be ideal in order to increase the rate of the reaction.
