Honors Cup Synthetic Proposal Section: 250 (Bill’s Lab) Group Members: Jordan Schaefer, Katie Pascaretta, Alex Weick, Carson Witte Title: Intermediate in the Overall Synthesis of Nanoputians Specifically Intermediate of “Lower Body”: Introduction: (what makes your target interesting?) This molecule is interesting because it is part of a larger experiment that shows mankind’s ability to manipulate organic molecules via the tools of chemical synthesis. Furthermore it uses the electrophilic aromatic substitution and other principles that we learned in our introductory chemistry course. We felt this reaction best exemplified the purpose of this lab and would be something we could feel satisfied with completing. Organic molecules make up mankind and chemistry has developed enough that it is possible to manifest the molecules in the image of man. Overall synthetic reaction scheme: (a Chemdraw or similar drawing of all three steps) NO2Br BrNO2NH2Br BrNO2Br2, CH3OOH97%NaNO2, H2SO4CH3CH2OH80%NH2SnCl2THF/CH3CH2OH89%123Br BrNH2Step 1 Synthetic transformation 1: (Chemdraw picture of first transformation) NO2Br BrNO2NH2Br2, CH3OOH97%NH21 Experimental 1 (notes if this transformation is not exactly the one reported in literature (e.g. on a different scale) and how it was modified): 5.0 g p-nitroaniline (0.036 mol)* in 45 mL* acetic acid stirred vigorously at 65oC. 12.48 g bromine (0.078 mol, 4 mL)* in 28 mL* acetic acid within 1 hour1. Hot water (5 mL)* added to redissolve precipitate after 1/3 of the bromine solution is added, the remaining bromine solution then added. Mixture then poured (with stirring) into water/ice slurry. Vacuum filtration used to isolate precipitate, washed with water, then left to air-dry. Yellow-green solid should be produced (approximately 10 g)*. *amounts divided by four in order to produce 0.5 – 1.0 g of target compound rather than experimental amount of 3.80 g 1time reduced from 4 hours to 1 hour to compensate for the reduced amounts of compounds and to fit lab time Expected yield: % g Produced in 97% yield from starting molecule-10 g Safety, disposal and green issues 1: Safety: 4-Nitroaniline Toxic Br2 Highly toxic, Corrosive, Harmful for the environment Disposal and Green Issues: Waste produced should be mostly, if not all, water, able to be disposed in either base or acid disposal containers. If multiple layers of waste appear, they should be separated and tested by water-drop to determine organic from inorganic. Any organic waste would be in the form of acetic acid, which is non-halogenated and able to be disposed of by normal means.Step 2 Synthetic transformation 2: (Chemdraw picture of second transformation) Br BrNO2NH2Br BrNO2NaNO2, H2SO4CH3CH2OH80%2 Experimental 2 (notes if this transformation is not exactly the one reported in literature (e.g. on a different scale) and how it was modified): 5 g of isolated precipate from Experimental 1 (2,6-dibromo-4-nitroanaline, 0.017 mol)* mixed with 55 mL* ethanol and 6 mL* concentrated sulfuric acid and heated to a boiling 90oC, stirred mixture. 4.0 g sodium nitrite (0.058 mol)* added as rapidly as allowed by the foaming. Mixture stirred at 90oC for 2 h1, then allowed to cool. Poured into ice water and the solids were collected by filtration, washed with water. The desired product was separated from the inorganic salts by dissolving it in boiling ethanol, then filtering the hot solution. Approximately 3.5 g* orange product should crystallize upon cooling. * amounts divided by four in order to produce 0.5 – 1.0 g of target compound rather than experimental amount of 3.80 g 1time significantly reduced from 36 hours in original experimental with consideration to lab time restrictions, yield not expected to be drastically affected when considering that the amounts of the compounds used were also reduced somewhat Expected yield: % g Produced in an 80% yield from the preceding step-3.5 g Safety, disposal and green issues 2: Safety: NaNO2 Oxidizing, Toxic, Harmful for the environment H2SO4 Corrosive CH3CH2OH Highly flammable, Harmful Disposal and Green Issues: Liquid waste would contain water and sulfuric acid, an acidic waste that would be disposed of accordingly. The inorganic salts can be disposed of via solid waste and do not require excessive precaution (anything beyond the normal amount of precaution taken). The ethanol used to dissolve the product is non-halogenated organic waste and is to be disposed of accordingly.Step 3 Synthetic transformation 3: (Chemdraw picture of third transformation) Br BrNO2SnCl2THF/CH3CH2OH89%3Br BrNH2 Experimental 3 (notes if this transformation is not exactly the one reported in literature (e.g. on a different scale) and how it was modified): 1.20 g of isolated solid from Experimental 2 (3,5-dibromonitrobenzene, 0.0043 mol)* mixed with 10 mL* ethanol and 10 mL* THF and stirred under air. 5.0 g tin(II) chloride (0.022 mol)* slowly added, then the mixture allowed to stir at room temperature for 2.5 h1. The solvent is evaporated via rotary evaporation, then an aqueous solution of sodium hydroxide added (excess). The mixture is stirred for .5 h2, then extracted with Et2O. Combined organic phases dried with MgSO4 and filtered. Solvent removed again via rotary evaporation. The target compound should then be afforded as a brown solid. * amounts divided by four in order to produce 0.5 – 1.0 g of target compound rather than experimental amount of 3.80 g 1time significantly reduced from original experimental time of 20 h due to lab time constraints and reduced compound amounts 2time divided by 4 from original 2 h due to lab time constraints and compound amounts being divided by 4 Expected yield: % g Produced in 89% yield from step 2-0.9 g (actual yield may be somewhat lower due to reduced time allowed for certain experimental procedures) Safety, disposal and green issues 3: Safety: CH3CH2OH Highly flammable, Harmful SnCl2 Corrosive THF Highly flammable, Irritant Disposal and Green Issues: Any ethanol waste is to be disposed of in non-halogenated waste and any chlorine-containing organic waste is to be disposed of in halogenated waste. Solids that result should be disposed of in solid waste, accordingly. The sodium hydroxide waste is to be disposed of in the bases waste, with the Et2O used for extraction being disposed of in non-halogenated
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