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23rd February 2012 @ 00:13
Reaction did not results in desired product. Reduced aldehyde observed and decomposition during attempted chromatography.

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Reductive amination of PMY 2-5 with glycinamide.

38-1.png

Reaction Start Time: 11.30 23/02/12
Glycinamide hydrochloride (132 mg, 1.20 mmol, 1.3 equiv.) and sodium hydroxide (55 mg, 1.38 mmol, 1.5 equiv.) were briefly refluxed in methanol (10 mL). PMY 2-5 (200 mg, 0.92 mmol, 1 equiv.) in MeOH (10 mL) was added to the still warm solution of glycinamide. After 2 hours, TLC shows some streaking of starting material on the plate (potential hydrolysis of imine on the plate). Mol. sieves added to the reaction. After a further 2 hours, no change by TLC. Sodium borohydride (38 mg, 1.01 mmol, 4.4 hydride equiv.) added to the reaction. After 4 days, the reaction was a brown slurry (significant grinding of the mol. sieves). 1M HCl (5 mL) was added and the reaction stirred for 30 minutes. The mixture was filtered and the filtrate concentrated under reduced pressure. The residue was dissolved in water (20 mL) and extracted with DCM (3 × 15 mL). The organic extracts were combined and washed with brine and dried (MgSO4) then concentrated under reduced pressure to a slightly brown oil (60 mg). Purified by chromatography (0-10% MeOH/DCM). Multiple spots obtained and split into 2 fractions; 38-1-A (trace), 38-1-B, brown oil (20 mg). 1H NMR is not consistent with desired product nor recovered alcohol.

TLC (25% EtOAc/hexane) visualised with UV and vanillin:
TLC 2 hours
TLC 4 days


NMR:
1H NMR crude
1H NMR PMY 38-1-B
1H NMR PMY 38-1-A


Risk and Hazard Assessment:
Risk Assessment


Reference:
doi 10.1016/j.ica.2006.01.006
Linked Posts
Attached Files
Scheme
Risk Assessment
TLC 2 hours
TLC 4 days
1H NMR crude
1H NMR PMY 38-1-A
1H NMR PMY 38-1-B