Exp4- Part A Prelab answers PDF

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Experiment 4 Mandatory prelab answers...

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Qu Questio estio estion n 1 (X. (X.X/3 X/3 X/3.0 .0 .0)) Question The following question requires you to research the reactants and products present in Experiment 4.

[FIGURE 1] Select the most appropriate answer(s) from the selection below. Refer to the OC1 practical manual to assist in the completion of your answers. Web resources such as Chemwatch and SigmaAldrich are useful references for the determination of the risks involved with handling these reactants/products.

Answer(s)      

Reactants: N-(4-hydroxyphenyl)acetamide, (A) 1-bromobutane, (B) NaOH and (C) Water Products: (D) N-(4-butoxyphenyl)acetamide Reactants: Paracetamol, (A) butane, (B) NaOH and (C) Ethanol Products: (D) N-(4-hydroxyphenyl)acetamide Reactants: Paracetamol, (A) 1-bromobutane (B) Butanol and (C) Sodium butyrate Products: (D) Butyloxy-4-Paracetamol Reactants: Paracetamol, (A) a Bromoalkane, (B) a base, (C) a solvent to dissolve the base. Products: (D) a secondary amide with an added alkyl chain Reactants: N-(4-hydroxyphenyl)acetamide, (A) an alkane, (B) a sodium salt, (C) a hydrating agent. Products: (D) an N-alkylated (with butyl group) paracetamol derivative The total risks involved with the reactants include: - Acute toxicity (Oral) - Irritation - Serious eye damage or irritation - Respiratory system toxicity - Flammable liquid - Chronic aquatic toxicity

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The total risks involved with the reactants include: - Acute toxicity (Oral only) - Fatal if swallowed. - Flammable - Fatal upon contact

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The total risks involved with the products include: - Skin sensitivity - Severe skin burns - Eye damage - Respiratory irritation - Corrosive

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The total risks involved with the products include: - Acute toxicity (Oral, Inhalation and Dermal) - Serious eye damage/irritation - Germ cell mutagen - Flammable liquid - Fatal upon exposure - Extremely flammable - Explosive risk

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Hydrobromic acid (HBr) forms as a consequence of the Williamson Ether synthesis reaction when using Bromine-containing hydrocarbons. Hydrobromic acid (HBr) poses no risk to this experiment and can be carried out without fume hood ventilation. Water is required to solvate the Na+ and OH- ions of NaOH.

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Qu Questio estio estion n 2 (X. (X.X/2 X/2 X/2.0 .0 .0)) Question The following image is a representation of the reaction conducted in Experiment 4: Preparation of N-(4butoxyphenyl)acetamide; Sn1 and Sn2 reactions of halohydrocarbons

[FIGURE 2] From the answers below, identify the most correct response(s).

Answer(s)  The apparatus shown above is a StarFishTM Multi-Experiment Work Station.  There are multiple forms of metallic heat-conducting base plates that can fit atop many hotplates due to multi-compatibility’  The flask setup contains a Water Manifold capable of distributing water to five condensers, each containing a quick-release valve.  A central support rod is used to position all experiments at right angles to the base-plate.  The final manifold (at the top) is utilized ONLY as an injection point for inert gasses and cannot be used for gas-escape or formation of a vacuum.  There is no secondary water manifold used for the collection of outflowing water from the condenser outlet valve. All outgoing water must be individually directed, with a rubber tube, to the nearest sink or collection device. Notes _____________________________________________________________________________________________ _____________________________________________________________________________________________ _____________________________________________________________________________________________ _____________________________________________________________________________________________ _____________________________________________________________________________________________ _____________________________________________________________________________________________

Qu Questio estio estion n 3 (X. (X.X/5 X/5 X/5.5 .5 .5)) Question Experimental flow diagrams are a critical tool for approaching any organic synthesis, serving as a concise scaffold and map for the direction of the experiment. Information useful for a reaction scaffold such as this may include the: - Reactants, reagents, solvents and their quantities, including the point at which they are added. - Products, by-products and an expectation of when they might form during the reaction. - The point at which the product is isolated and what techniques are required to purify the product. For the experimental flow diagram below, which represents the ideal scaffold for Experiment 4, describe the status of the reaction from stage 1 to stage 5, also describing the steps taken between stages.

[Figure 3] Please select the correct answers from the selection below: Answer(s) 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.

3.75 g of Paracetamol + 20 mL of 95% EtOH in a 100 mL round bottom flask. Add a solution of 1.75 g of NaOH + 2 mL of Water Heat Formation of conjugate phenoxide of paracetamol and water. Dropwise, add 2.85 mL (3.63 g) of 1-bromobutane Reflux for 1 hour Cooling with ice to 0o C will encourage crystallisation Crude mixture of N-(4-butoxyphenyl)acetamide, NaOH, Water and unreacted materials Filtration under vacuum with washing of solid with water Crude N-(4-butoxyphenyl)acetamide Mother liquor containing NaOH, water and unreacted materials which can be discarded.

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Qu Questio estio estion n 4 (X. (X.X/2 X/2 X/2.5 .5 .5)) Question For the experimental flow diagram below, which represents the ideal scaffold for Experiment 4, describe the actions that must be undertaken at Step 7 to fully characterize the final product.

[Figure 3] Please select the appropriate answer(s) from the selection below: Answer(s)        

Identify the yield of the final product. Determine the melting point of the final product. Submit the correctly labelled sample to your demonstrator. Describe the smell of your final product. Taste test your final product as it will have a noticeable flavour Perform infrared spectroscopy Dry the crystals at 80o C for 10 minutes Dry the crystals at 169o C for 10 minutes.

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Qu Questio estio estion n 5 (X. (X.X/0 X/0 X/0.5 .5 .5)) Question The reaction conducted in Experiment 4 utilizes a Phenolic compound (Paracetamol) as the substrate for an Oalkylation reaction. In this reaction, which of the following answers (from the selection below) is the Nucleophile?

Answer(s)    

Sodium phenoxide Protonated Paracetamol Neutral Paracetamol Basic Bromobutane

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Qu Questio estio estion n 6 (X. (X.X/0 X/0 X/0.5 .5 .5)) Question The reaction conducted in Experiment 4 utilizes a Phenolic compound (Paracetamol) as the substrate for an Oalkylation reaction. In this reaction, which of the following answers (from the selection below) is the Electrophile?

Answer(s)    

Basic Paracetamol 1-bromobutane The leaving group of 1-bromobutane The terminal methyl carbon of 1-bromobutane.

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Qu Questio estio estion n 7 (X. (X.X/0 X/0 X/0.5 .5 .5)) Question The reaction conducted in Experiment 4 utilizes a Phenolic compound (Paracetamol) as the substrate for an Oalkylation reaction. In this reaction, which of the following answers (from the selection below) is the Leaving group?

Answer(s)    

Bromide anion Bromide cation Proton cation (from paracetamol after deprotonation with base) Any of the four available benzene ring protons (Ph-H) available on paracetamol.

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Qu Questio estio estion n 8 (X. (X.X/0 X/0 X/0.5 .5 .5)) Question The reaction conducted in Experiment 4 utilizes a Phenolic compound (Paracetamol) as the substrate for an Oalkylation reaction. In this reaction, which of the following answers (from the selection below) is the correct way in which to rinse your final product? Answer(s)    

With water at 37o C With water at ~0o C With water at 20-25o C With chloroform at 20-25o C

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Ap Appen pen pendix dix Figure 1 – Paracetamol undergoing reaction with reactants (A, B and C) to form O-alkylated Paracetamol (D).

Figure 2 – In the following diagram, all a StarFish is shown. [Source: Google Images]

Figure 3 – In the following flow diagram, all stages from 1-5 and steps from 1-7 are labelled....