Question

1. Analyze the attached product NMR spectrum. Justify the structure of your final product and deduce the identity of your unknown starting material.

2. Provide a reaction mechanism using the starting material that you deduced in Qu. 1.

Experimental Procedure In this experiment. Vou will perform a double reductive amination reac an unknown aldehyde to form the corresponding amine product determine the identity of the unknown starting material. reaction between ethylenediamine and oduct. Analyze the lab data obtained to HẠN NHA RE YO -NH HN- OH Amberlyst 15 Ethanol, NaBHA -OH HO Unknown Carbonyl Compound (2 equivalents) Structures of Possible Unknown Starting Materials: HO. ОН 6o.log/mol 0.8999/mL. Place 5.5 mmol of ethylenediamine into a 50 mL round bottom flask with 10 Add 11.0 mmol of the unknown carbonyl compound (MW provided or round bottom flask with 10 mL of ethanol, and a stir bar. g of Amberlyst 15. Stir the mixture at reflux for 15 minutes then allov na (MW provided on the vial) to the flask followed by 0.5 sodium borohydride in small portions to the reaction mixture. [Note: some buo a rerux for 15 minutes then allow the flask to cool. Add 0.38 g of solution at room temperature for another 15 minutes. Then quench the mixture. [Note: some bubbling may occur] Stir the dropwise addition of 2M HCI (10 mL). Transfer the reaction mixture to a separato another 15 minutes. Then quench the reaction in the fume hood by ml). Transfer the reaction mixture to a separatory funnel and add 15 ml of ethyl acetate. Extract the organic phase consecutively with 2 x 10 mL of water. Separa the aqueous phases and add 10% sodium hydroxide to this phase until al ely with 2 x 10 mL of water. Separate and combine 10% sodium hydroxide to this phase until a basic pH is obtained. Then extract the solution with 15 mL of ethyl acetate and dry the organic phase with sodium filtering and evaporating the solvent under reduced pressure, analyze the purity of the p and dry the organic phase with sodium sulfate. Prior to by TLC (compare against a standard of the starting unknown carbonyl compound). Note: You your knowledge and experience to determine a suitable TLC eluent. Once the product is dry, oh yield and an IR spectrum. Your TA will provide the corresponding proton NMR for analysis and struct determination.

Answer 1

solution: NH2 Ly HAN 2 OH HO Amberlyst EtoH, NUBHH eight aromatic proton signal he The NMR spectrum contain eight aromatic proton si the benzene ring is disubstituted. The caliphatic region contain 4H et = 40 4.0 ppm it the proton carbon is in between aromatic ring and nitrogen citum he fette 2CH2 = The aliphatic region contain 4H at ~ 2.8-2.9 it ihan the proton carbon attached to nitrogen are 2 CH2 group . The structure of unknow starting material is OH and the : @ 6 ③ d @ structure of final compound is, © OH OM HH 7 4 0 ppm 44 ie 2 CH2 group attached to nitrogen and aromatic ring, x 2.8-2.9 ppm 44 h. 20H2 group attached to nitrogen ñ 6.8 - 595 ppm 2h her 9.614 ppm 24 903 ppm 24 6.8 - 6.85 ppm 24 0 ž 6.95ppm 24

Mechanism: step-y I mine formation NH OH AT OH NH2 -NH2 NH2 th H OH OH HO - Imine. NABH4 -NH step-2 OH Step-1. Reaction of in Etoh to ea Etol. aldehycle with form imine. amine in In reaction prensence of the proton amberlyst source is step-2 Reduction of imine into amine in NUBHA The overall reaction is Reductive amination