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24th October 2012 @ 06:25
Conversion of carboxylic acid PMY 59-3 to the primary amide using EDC and ammonium hydroxide as for PMY 60-3. [b]Reaction Start Time: 17.05 24/10/12[/b] PMY 59-3 (102 mg, 0.34 mmol, 1 equiv.) was stirred in DCM (7 mL, 0.05M). Partial solution. EDC.HCl (85 mg, 0.44 mmol, 1.3 equiv.) and HOBt (approx 4 mg) was added. EDC.HCl dissolves quickly. After 10 mins, clear solution with some needles. After 20 minutes, 28% NH4OH (1 mL) was added and the reaction left to stir. After overnight stirring, saturated NH4Cl(aq) was added. The layers were separated and the aqueous layer extracted with DCM (3 × 10 mL). The combined organic layers were washed with brine, dried (MgSO4) and concentrated to a pale yellow solid (113 mg). 1H NMR shows multiple products, peaks close to SM and PMY 60-3; inconclusive. Purified by chromatography on silica (5% MeOH, 1% NH4OH/DCM) gave slightly yellow solid (84 mg). 1H NMR mainly consistent with PMY 60-3 and impurities. Further chromatography on silica (2-5% MeOH/DCM) gave an early running fraction and 2 other fractions, -A and -B, white solids. [b]TLC visualised with UV and vanillin[/b] [data]3626[/data][data]3630[/data] 10% MeOH/DCM [data]3628[/data] 10% MeOH/1% NH4OH/DCM [b]NMR:[/b] [data]3632[/data][data]3634[/data] [b]See Also:[/b] [blog]5097[/blog] [blog]4909[/blog] [blog]4903[/blog] [blog]4004[/blog] [blog]969[/blog] [b]Risk and Hazard Assessment:[/b] As for: [blog]960[/blog]
Attached Files
TLC crude MeOH/DCM
TLC column 2
1H NMR crude
1H NMR column 1