Exp053

=Objective= To study the chemical interaction between N-(//tert//-butoxycarbonyl) glycine and //tert//-butyl isocyanide in Methanol-D4 by NMR spectroscopy. =Procedure= One molar methanol-D4 solutions of [|tert-butyl isocyanide] (113uL, 1mmol) and [|Boc-Gly-OH](175mg, 1mmol) in CD3OD are prepared in separate 1 dram vials. 800uL of the solutions are used to obtain initial NMR spectra. Then 400uL of each solution is transfered to a clean nmr tube and shaken vigorously for a few seconds, the reaction is monitored by NMR spectra. =Results= tert-butyl isocyanide [|HMR] [|CMR] Boc-Gly-OH [|HMR] [|CMR] [|t = 02min] [|t = 05min] [|t = 13min] C NMR [|t = 17min] [|t = 39min] C NMR [|t = 46min] [|t = 49min] [|t = 61min] [|t = 85min] C NMR [|t = 161min] C NMR [|t = 172 min] [|t = 322 min] [|t = 430min] [|t = 20h 21min] C NMR (Overnight run) [|t = 24h 07min]
 * 50A (Boc-Gly-OH + //tert//-butyl isocyanide)**

Spectral Overlays
[|Overlay1] [|Overlay2] =Discussion= From the overlays it is obvious that //tert//-butyl isocyanide does not exhibit chemical reactivity towards Boc-Gly-OH. All peaks in the starting materials remain unchanged over a 24 hours period .This is in sharp contrast to 2-morpholinoethyl isocyanide which looses its isonitrile identity in the presence of Boc-Gly-OH within a few minutes(Exp049). =Conclusion= //Tert//-butyl isocyanide like benzyl isocyanide (Exp050) may be used as an isonitrile of choice for performing Ugi reactions involving Boc-Gly-OH. =Log=

2007-01-24
11:00 - Obtained a 1H NMR and a 13C NMR of [|tert-butyl isocyanide] and [|Boc-Gly-OH] in methanol-d4. 14:20 - Added [|Boc-Gly-OH] solution to [|tert-butyl isocyanide] solution. 14:22 - Obtained H NMR (t = 2min) 14:25 - Obtained H NMR (t = 5 min) 14:33 - Obtained C NMR (t = 13min) 14:37 - Obtained H NMR (t = 17min) 14:59 - Obtained C NMR (t = 39min) 15:06 - Obtained H NMR (t = 46min) 15:09 - Obtained H NMR ( t = 49min) 15:21 - Obtained H NMR (t = 61min) 15:45 - Obtained C NMR (t = 85min) 17:01 - Obtained C NMR (t = 161min) 17:12 - Obtained H NMR (t = 172min) 19:42 - Obtained H NMR (t = 322min) 21:30 - Obtained H NMR (t = 430min)

2007-01-25
10:41 - Obtained C NMR(t = 20h 21min) 14:27 - Obtained H NMR (t = 24h 07min)

=Tags=

[|t-butyl isocyanide][|InChI=1/C5H9N/c1-5(2,3)6-4/h1-3H3] [|Boc-Gly-OH][|InChI=1/C7H13NO4/c1-7(2,3)12-6(11)8-4-5(9)10/h4H2,1-3H3,(H,8,11)(H,9,10)]

media type="custom" key="17584"