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24th May 2010 @ 11:53
Creation date: 25/05/2010 19:45 [data=size:500x180]96[/data] [data=size:500x180]98[/data] [b]Hazard and Risk Assessment:[/b] Reaction Class: 2 Hazards: X Irritant, C Corrosive, F Flammable Risk rating: U = Unlikely Start time (Trial 1-3): 18:35 Start time (Trial 4): 19:00 Start time (Trial 5-7): 19:30 End time: 10:00 26/05/2010 Trial 1-3: [b]MW14-3-79[/b] (50.0 mg, 194 µmol) was dissolved in toluene (2 mL), phenylphosphinic acid (1, 2, 5 eq., see table) was added and stirred at rt - 1,2 clear pale yellow solution; 3 cloudy pale yellow solution - after 16 h: 1 and 3 cloudy solutions, get clear after heating, work-up TLC (EA:MeOH:TEA = 1:1:0.02) --> no conversion, starting material Trial 4: [b]MW14-3-79 [/b](50.0 mg, 194 µmol) was dissolved in trifluoroacetic acid (1 mL) and stirred at rt --> clear orange solution - after 16 h: brown solution, work-up TLC (EA:MeOH:TEA = 1:1:0.02) --> nearly complete conversion, less starting material 1H NMR: broad signals, unselective conversion, no starting material monitored Trial 5-7: [b]MW14-3-79[/b] (50.0 mg, 194 µmol) was dissolved in toluene (2 mL), p-TsOH (1, 2, 5 eq., see table) was added and stirred at rt First cloudy solutions, then brown precipitate - after 16 h: brown precipitate on the bottom of the vials, colorless precipitate on the wall, not soluble by heating TLC (EA:MeOH:TEA = 1:1:0.02) --> nearly complete conversion, less starting material, heterocyclic product ? Same Rf / stain color like cyclized amine 1H NMR: product with impurities, good conversion [data]104[/data][data]106[/data][data]108[/data] Work-up: - Basic work-up, 2 N NaOH solution, extraction with chloroform, dried over sodium sulfate TLC (EA:MeOH:TEA = 1:1:0.02) from the chloroform solutions, stain: Ceric ammonium molybdate [data=size:100x150]100[/data] [data=size:100x150]102[/data]
Attached Files
Reaction Scheme
Table1
TLC1
TLC2
1H NMR T5
1H NMR T6
1H NMR T7