I need to find the limiting reagent, molar…
I need to find the limiting reagent, molar equivalent/mole, theoretical yield, and percent yield of aniline and the unknown sample. The starting aniline is 0.5g and the end product is 0.58g. The starting unkown is 0.5g and the end product is 0.56g. Synthesis of an Analgesic by Acetylation of Aniline Introduction: Acetanilide is an analgesic that was formally known as Antifebrin1 and is structurally similar to acetaminophen (or Tylenol). However, unlike acetaminophen, acetanilide is toxic. Acetanilide is prepared from aniline using an acetylation reaction. Acetylation is often used to place an acetyl protecting group on primary or secondary amines to reduce their reactivity toward oxidizing agents or electrophiles. 1. Cahn, A; Hepp, P. (1886), “Das Antifebrin, ein neues Fiebermittel”, Centralbl. Klin. Med. 1886, 7, 561-65 Objective: In part 1 you will convert aniline to acetanilide using an acetylation reaction described below. In part 2 you will be given an unknown aromatic amine from table 1 below. The amine will be converted into its acetamide analog also using the acetylation procedure described below. Your objective is to compare the two reactions and determine the identity of the unknown amine/acetamide product. Procedure: Reagents: ? ? ? ? Aniline HCl (concentrated HCl is 37% w/w) Acetic anhydride Sodium acetate Part 1: Dissolve 500 mg of aniline in 14 mL of water. Note that aniline is immiscible in water and two layers should be observed. Assisted by your GSI add 0.45 mL of concentrated hydrochloric acid and stir. Measure out 0.6 mL of acetic anhydride and prepare a solution of 530 mg of sodium acetate in 3 mL of water. Add the acetic anhydride to the solution of aniline hydrochloride in water, mix by swirling, and immediately add the sodium acetate solution. The solution becomes white as acetanilide precipitates. Chemistry 216 Cool the solution in an ice bath and collect the solid acetanilide by vacuum filtration. Be sure to weight the crude solid before purification. Purify by recrystallize from a minimal quantity of ethanol 95%. If crystals don’t form in a few minutes - it may be necessary to add a small amount of water. Collect the pure crystallized solid by vacuum filtration. Place the solid in a labeled vial and allow it to dry until the next lab session. Don’t forget to obtain the mass of your final pure product so that you can calculate % yield. Characterize the product using TLC, melting point, the Beilstein test and Infrared Spectroscopy. The product should be co-spotted against a pure sample of starting material. Determine the appropriate solvent or solvent mixture to use as the eluent. Part 2: Use the above procedure for acetylation of the substituted unknown aniline. Exact quantities cannot be calculated since the starting material is an unknown. Be sure to retain your unknown starting material until you have characterized all reaction products. If you don’t obtain product you may need to characterize your unknown starting material to determine it’s identity. Remember that your starting material doesn’t just disappear! If your reaction didn’t work you should be able to recover something. If it isn’t your product than it should be either unreacted starting material or an undesired product. In any case you aren’t finished with any 216 experiment until you isolate and characterize whatever exists in your reaction mixture so that you can figure out what happened. If you recrystallization doesn’t work – try again or isolate your crude product using an extraction. The Beilstein test is used to detect the presence halogens in your unknown compound. To perform the Beilstein test first clean a copper wire by holding it briefly in a flame. Touch the wire to a sample of the compound (your compound should be dry and free from solvent since halogenated solvents will give a false positive) and return it to the flame. A blue-gree color in the flame indicates the presence of a halogen. It is a good idea to test the procedure on a compound known to contain a halogen before trying it on your own compound. Reagents: Compound CAS Number 62-53-3 Mol. wt. (g mol-1) 93.13 Concentration or density 1.022 g/mL m.p. or b.p. (°C) 184 (bp) Aniline Hydrochloric acid 7647-01-0 36.46 37 wt. % & 1.2 g/mL >100 (bp) Acetic anhydride 108-24-7 102.99 1.08 g/mL Sodium acetate solution Acetanilide 127-09-3 82.03 -- 138-140 (bp) -- 103-84-4 135.16 -- Chemistry 216 113-115 (mp) SAFETY NOTES Corrosive, acutely toxic, environmental hazard Corrosive, acutely toxic, handle with extreme caution! Flammable, corrosive, toxic toxic toxic Table 1. Unknown Amines with respective boiling and melting points and melting point for the corresponding acetamide product. Chemistry 216 Hide preview Additional Requirements Level of Detail: Show all work Other Requirements: I can provide any additional information that you will need but I need all the calculations for both aniline and unknown aniline.