Experiment 4: Heating system Under Reflux- Synthesis of Salicylic Acid solution from Wintergreen Oil
Section 07, Thursday afternoon
Research laboratory experiment performed on: Friday, January nineteen, 2013
Lab report published on: Thursday, January twenty four, 2013
Before the man made aspirin these days, salicylic acid solution, which is the top ingredient seen in aspirin, was extracted normally from methyl salicylate found in Wintergreen petrol, which could be found in certain plants. The purpose of this kind of lab test is to prepare salicylic chemical p from the all-natural starting material, methyl salicylate, and assess it while using salicylic acidity produced from the artificial compound benzene (obtained through petroleum refining). Depending on the two reactions of acetylsalicylsaure synthesis displayed below, methyl salicylate and benzene talk about a common intermediate which is salicylic acid:
To be able to prepare salicylic acid via wintergreen oil, an organic activity must be accomplished. This is done first by simply separating salicylic acid coming from methyl salicylate, followed by the purification. The separation is possible by performing a reflux of a answer of methyl salicylate and sodium hydroxide. After the reflux is finish, sulphuric acidity will be included in the refluxed solution, which will cause the salicylic acid to precipitate. This will likely then end up being filtered through suction filtration. Once the product has dried out, purification should be done by recrystallization; dissolving the merchandise in a lowest amount of hot solvent (water), after which filtering once again through suction filtration. Finally, to finish the main aim of the test, which is to evaluate the ready product with a standard (salicylic acid by benzene), a great analysis must be done by measuring the burning point of the crystals and of the standard. This is certainly fulfilled by using capillaries opened at one end made up of a very tiny amount of both examples (dried merchandise and a 1: 1 combination of the dried product with standard), and inserting these people into the melting-point apparatus, in which their shedding point could be read on the thermometer. Outcomes:
| Molecular weight (g/mol)| Melting level (oC)| Hot point (oC)| Density (g/mL)| Methyl salicylate| 152. 1| -8| 223| 1 . 174
Salicylic acid| 138. 1| 159| -| -
Mass of watch-glass (g)| Mass of watch-glass + initial merchandise (g)| Mass of watch-glass + uric acid (g)| Melting point selection of crystals (oC)| Melting point range of one particular: 1 mix (oC)| twenty nine. 677| 40. 808| 30. 876| 154-157| 158-159
* Precipitation of salicylic acid developing from addition of sulphuric acid 2. crystals showing on the surface area while cooling in ice-bath
Mass of product, genuine yield (g)| Percent yield (%)| Burning point range (oC)| 1 ) 199| eighty six. 82| 154-157
*Methyl salicylate =MS, Salicylic acid= SA
1 ) 521g MS x (1mol MS/152. 1g MS) by (1mol SA/1mol MS) sama dengan 0. 01 mol SA Mass of SA:
zero. 01mol SA x (138. 1g SA/1mol SA) sama dengan 1 . 381g Salicylic acid solution
Percent deliver = (actual yield/ theoretical yield) by 100%
= (1. 199g/ 1 . 381g) x completely = eighty six. 82 %
Percentage mistake = [(Actual produce вЂ“ theoretical yield)/ theoretical yield] x 100% = [(1. 199g вЂ“ 1 . 381g)/ 1 . 381g] x fully = 13. 18% Device:
Discussion and conclusion
Methyl salicylate (which comes from wintergreen oil) and benzene will be two compounds from which salicylic acid can be obtained from. The between the two is that you can be found the natural way in vegetation (methyl salicylate) and the various other is synthetically produced (benzene). The question is carry out they produce the same ideal product (salicylic acid)? This lab research consisted of setting up salicylic chemical p from a methyl salicylate sample and, and assessing it with salicylic acid made from benzene by computing their melting points at the same time. In order to do therefore ,...
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