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15th July 2010 @ 06:05
Testing various intermediates of PZQ (derivatives) with a achiral Bronstedt-acidic thiourea catalyst [url=http://www.ourexperiment.org/racemic_pzq/496][b]MW43-1[/b][/url] as pretest for chiral derivatives of the catalyst - NMR-monitored experiments [data=size:500x200]346[/data] [data=size:500x150]348[/data] [b]Hazard and Risk Assessment:[/b] Reaction Class: 2 Hazards: T Toxic, X Irritant, C Corrosive Risk rating: U = Unlikely Start time: 4:30 PM 15/07/2010 End time: 10:30 PM 16/07/2010 [b]General Procedure:[/b] Each of the compound [b]MW7, [url=http://www.ourexperiment.org/racemic_pzq/241]MW29-4[/url], [url=http://www.ourexperiment.org/racemic_pzq/171]MW14[/url], [url=http://www.ourexperiment.org/racemic_pzq/386]MW40-1[/url][/b] (75.0 µmol) shown in Table1 was solved in CDCl3 (~0.5 mL) in a NMR tube and [url=http://www.ourexperiment.org/racemic_pzq/496][b]MW43-1[/b][/url] (3.8 mg, 8.0 µmol, 10 mol%) was added and heated to 60°C for 18h. [b]MW44-1 – MW44-4[/b]: no conversion was monitored (by 1H NMR) -> MeSO3H was added (5.2 µL of a 5% solution in CDCl3, 384 µg, 4.0 µmol, 5 mol%) After 4 h at r.t. no conversion was monitored -> heated to 60°C Comparison of the Reaction NMRs [data=text]352[/data] [data=text]354[/data] [data=text]356[/data] [data=text]358[/data] [b]Results:[/b] No conversion of the starting material was observed
Attached Files
Reaction Scheme
Table1
1H NMR comparison MW44-1
1H NMR comparison MW44-2
1H NMR comparison MW44-3
1H NMR comparison MW44-4