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29th October 2012 @ 04:51
Friedels-Craft Acylation of AEW1-1 to give MNR51-1 See [url=http://malaria.ourexperiment.org/tcmdc_ap/4223/Repeat_Preparation_of_14Fluorophenyl25dimethyl1Hpyrrole_AEW_11.html]- Synthesis on AEW1-1[/url] [b]Hazard Assessment[/b] [data]3642[/data] [b]Procedure[/b] reaction on at 3pm 29/10/12 AlCl3 (1.06 g, 7.93 mmol) was added to a solution of succinic anhydride (0.436 g, 4.36 mmol) and AEW1-1 (0.750 g, 3.96 mmol) in DCM (20 mL). The reaction mixture was stirred at room temperature for 18 h at which time there were still traces of SM in the TLC but it was thought best to work up. The reaction mixture was concentrated at reduced pressure then water (6 mL) was added and the mixture cooled to 0°C and acidified with HCl (37%, 3 mL). The mixture was allowed to warm to room temperature and stirred for 30 min. No solid crashed out, only a red insoluble oil formed. EtOAc (15 ml) was added and the organic laer extracted. The aq layer was then extract with EtOAc (3 x 15 mL), the organics were then combined, dried of magnesium sulphate, filtered and concentrated to give the crude as a red solid (1.5 g) Column 40-60% EtOAc/Hex frac 1-5 - 0.338 g, 1.79 mmol, 45% - recovered starting material - dark red/brown crystals frac 11-19 - 0.340 g, 1.17 mmol, 30% - product (54% based on SM recovered) - off white/pale red solid Fractions 20 onwards had white precipitate but did not show up on UV. Still need to collect. Product is poorly soluble in CDCl3 but good enough for a quick NMR. [b]NMR[/b] Starting material - AEW1-1 1H [data]3636[/data] Column - Fracs 1-5 - Recovered starting material [data]3662[/data][data]3670[/data] Column - fracs 11-19 - Product [data]3664[/data][data]3666[/data][data]3668[/data][data]3672[/data] [b]Conclusion[/b] Friedels-Craft Acylation of AEW1-1 works to some extent. A longer reaction time or elevated reaction temperature may help drive the reaction to completion. It should also be noted that the AlCl3 used was from a rather old bottle and it was not perfectly white. Reaction closed - 31/10/12
Attached Files
mnr_aew1-1_1H.pdf
mnr51-1_table.PNG
MNR51_scheme.png
HIRAC MNR51.pdf
mnr51-1_frac1-5_sm_1H.pdf
mnr51-1_frac11-19_1H.pdf
mnr51-1_frac11-19_13C.pdf
mnr51-1_frac11-19_19F.pdf
mnr51-1_frac1-5.zip
mnr51-1_frac11-19.zip
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