Synthesis of Salicylic Acid

Synthesis of Salicylic dose from Wintergreen Oil Abstract The purpose of this experiment is to progeny methyl radical radical salicylate (wintergreen oil) and by heating it nether reflux with NaOH as a solving, and then cooling the categorization with H2SO4 as another solvent, synthesize salicylic sexually transmitted disease. The final standard involves purify the harvest-time to produce as pure a warning of salicylic acid as possible. This process allowed for the successful production of 1. 406g salicylic acid, an 82. 70% yield. The nuclear magnetic resonance and IR both produced images that correlate with the cognise spectrums indicating a pure product.The warming render post was slightly wider, though did encompass the accepted warming point values. Discussion Reaction OH O OCH3 2) H2SO4 1) 2NaOH OH O OH 1. 595 ml methyl salicylate is reacted with sodium hydroxide by heating it under reflux. The sodium ions overhead the methyl group from the methyl salicylate overdue to the greater attraction amid the sodium cation and the slightly detrimental charge on the oxygen compargond to the O-CH3 amaze that had previously existed. This reaction produces disodium salicylic acid, methyl hydroxide and water molecules.The sodium crystals that ashes are visible as the white particulate matter seen as soon as the two chemicals are mixed. Heating of the marrow under reflux increased the reaction rate as did the use of the solvent to increase the frequency of molecules being ripped off the original substance and suction them into their new molecular formations. At this point the wintergreen smell has dis protrudeed from the mixture indicating a rapid decline in the amount of methyl salicylate precede in the reaction. When the sulfuric acid (pH . ) is added to the disodium salicylic acid (pH 5-6), the two sodium atoms are replaced by total heat atoms creating salicylic acid and sodium sulfate and lower the pH of the solution to 2. The sodium catio ns are now more attracted to the slightly negative charge on the two oxygen anions on the SO42- ions than to the disodium salicylic acid and the hydrogens take their place. The ice bath kept the temperature low enough that the salicylic acid remained square(p) and the sulfuric acid components liquid, allowing for a final product with the most innocence possible.Determining limit reagent 1. 595 ? 15. 0 ? numerate of methyl salicylate used 1 Amount of sodium hydroxide 2. 13 g 1. 174 Theoretical yield real yield 1. 406 g Percent yield = 1. 873 ? 1. 406 ? 1. 700 Melting point cranial orbit of purified product 150-162C Mixed run point ply with salicylic acid 153-160C The melting point range of the synthetic salicylic acid includes the school text value of 159C.Although a greater variance was seen with the synthetic salicylic acid melting point range (range=12C) versus the provided salicylic acid (range=7C), the full range of the provided salicylic acid fell inwardl y the range of the synthetic salicylic acid, indicating a relatively pure product. It should be noted that optimally the melting point range should be slightly narrower. Loss of product occurred due to loss at each transfer step including, crystals stuck to the vacuum filter, crystals sticking to the glass assert rod for pH testing as well as the coat spatula used for recrystallization.While washing the crystals, some loss would also be seen due to the slight solubility of salicylic acid. I R 10 0 = 8 2. 7 0% (138. 1 / ) = 1. 700 (152. 1 / ) 1 = 31. 95 NaOH = 1. 873 ***limiting reagent*** PE A K 1 2 3 4 5 POSITION (cm-1) 748. 245 1204. 33 1654. 62 2850. 27 3235. 00 BOND (MODE) C-H bend (redolent) C-O go C=O stretch O-H stretch (carboxylic) O-H stretch (on phenol) ASSIGNMENT 1 2 3 4 5 3 2 1 4 1 1 5 NMR Chemical berth (ppm) 10. 5 8. 0 7. 5 6. 9 Integration 2 1 1 2 Multiplicity/splitting Singlet Doublet troika Triplet engagement 1 2 3 4 3 4 1 4 2 1 NMR Discussion As signment 1 The singlet rash is located at 10. 5 ppm and is designate to the hydrogens linked to the two single bonded oxygens. These two can share this single flowering because the hydrogens are constantly swapping places with each other due to their position within the molecular structure and if the NMR was magnified, two peaks could be seen.Assignment 2 The peak located at 8. 0 ppm is a doublet peak delegate to the hydrogen bonded to carbon on the aromatic ring closest to the carboxylic group. It is shifted . 5-. 6 ppm downfield of where hydrogens on a benzene ring would normally appear due to de-shielding by the close carboxyl group. Assignment 3 The 7. 5 ppm triplet peak is indicative of the hydrogen bonded to carbon on the aromatic ring closest to the phenol group, again due to de-shielding by the nearby phenol group.The extra peak is likely due to the interaction of the O-H bond with the C-H bond. Assignment 4 6. 9 ppm has a triplet peak and is assigned to the two remaini ng C-H bonds on the aromatic ring. Conclusion The final product was attaind by taking advantage of the electron affinity and nucleophilic properties of the chemicals and especially the solvents to create transition states to allow for a faster, more stable reaction. Heating of the substance under reflux also increased the reaction rate.The melting point range contains the textbook value of salicylic acid and the IR and NMR matches the known IR/NMR for salicylic acid. This supports the purity of the substance created. The absence of the wintergreen fragrancy indicates an absence of the methyl salicylate. After completion of this experimental process, 1. 406 g of salicylic acid was created from the initial 1. 595 g methyl salicylate which equates to an 82. 70% yield, a successful result.