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8th December 2016 @ 23:56
Compound Mw (g/mol) mmol mL g equiv Starting Material 526.6501 0.09494   50mg 1 HCl-Ether 38 0.0312 0.156 (2M HCl)   3.3 Product Theoretical Values 339.17 0.09494   32.2mg 1 dioxane 88.11   2 mL (4M)   3.3 Product Actual Value 339.17 0.07371   25.0 mg 78% Yield   November 30, 2016 Procedure: Dissolve 50 mg of the starting material in 500 uL of anhydrous diethyl ether and place system under argon. Add 2M HCl-Ether (0.1 mL) dropwise to the solution while stirring. Age solution for 2 hours at room temperature and the reaction was monitored with TLC. Left in fridge overnight. 100% EtOAc solvent system, silica gel plate, UV visualization S → Starting Material; C → Co-spot; P → Product. This TLC is similar to the first deprotection we did, which we deemed unsuccessful in taking out that BOC group, though there was success in knocking out the THP. This can be determined by comparing the S and C to the P. The S and C show a dark spot higher up on the plate; P shows one lower with a faint smear above it. This suggests that the THP group was successfully knocked out and the BOC group only partially (this agrees with our NMR and GCMS results from the first deprotection). Another TLC was done to confirm this hypothesis and determine if the reaction should be hit harder to take out both the THP and BOC group.    100% EtOAc solvent system, silica gel plate, dipped in ninhydrin and treated with heat S1→ Original Purified Starting Material; S2→ Starting Material from First Deprotection; C → Co-spot; P → Product. Treating the TLC plate with ninhydrin and heat results in two dark spots on the base line of S2, and C and a faint brown spot on the base line of P. The difference in intensity can be attributed to concentration. The presence of these spots after being treated with heat suggest that the BOC group was successfully knocked off, and resulted in the formation of an amine, which is the desired product. The BOC was only successful knocked off with heat on the plate. To do this on a larger scale, these results suggests the deprotection reaction must be hit harder; the reaction must be done under heat with the addition of dioxane.   December 5, 2016 We were unsuccessful in removing the BOC with extra time . This suggests the reaction needs to be hit harder, specifically with the addition of dioxane and ran in an oil bath. Added 2 ml of 4M Dioxane and 0.1 mL of HCl  dropwise to the product while stirring and place in an oil bath at 50 degrees Celsius. System was placed under argon.  The reaction was monitored with TLC. After 2 hours at 50 degrees, TLC indicated that there was still starting material. The temperature was raised to 102 degrees to induce reflux. The reaction was then left to reflux for 45 minutes. After 45 minutes the reaction turned brown and a TLC was taken. The results of the TLC and a ninhydrin test suggest that the complete deprotection was successful due to the disappearance of the high Rf spot observed in previous attempts.   December 7, 2016 Mass Spec:  [data]20345[/data]   The peak at m/z 340 suggests that we successfully removed the Boc protecting group that we had trouble removing in the past. It is possible, however, some residual Boc protecting groups were removed in the mass spec instrument, so the product was also analyzed with proton and carbon NMR.   December 8, 2016  NMR: Still to be determined  
Attached Files
Deprotection.pdf