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12th April 2012 @ 08:07
Resolution of MNR26-1 with (+)-dibenzoyl-D-tartaric acid (MNR5-1)

*SM recovered from unsuccessful resolutions in MNR27

MNR30-1%20scheme.png



Hazard and Risk Assessment:
As for MNR2-1

MNR26-1 (0.60 g, 2.29 mmol) and MNR5-1 (1.1 g, 2.29 mmol) was dissolved in a mixture of IPA (20 mL) and hexane(5 mL) and heated till the reagents went into solution. After standing at room temperature overnight a dark solid was visible but not crystals. This solid was filtered off and washed with IPA:Hex (50:50) to give a light brown solid (0.547 g). A portion of this solid (50 mg) was mixed with water (2 mL) and taken to pH 12 with the addition of NaOH solution (2M) and extracted with EtOAc (4 ml x 3). The organic fractions were combined, dried over magnesium sulphate, filtered and concentrated under reduced pressure to give a light brown oil (17 mg) Chiral HPLC analysis of this showed no ee.

mnr26-1_110412.pdf

mnr30-2_firstfilter.pdf

*note - there has been problems with the HPLC pump and the pressure is jumping between 200-3000 psi. This is the likely reason for the change in retention times. See the standard below for a better rac trace

Upon standing white crystals had started to form in the original filtrate. This were filtered and washed with IPA:Hex (50:50) to give a white solid (0.063 g). This was mixed with water (2 mL) and taken to pH 12 with the addition of NaOH solution (2M) and extracted with EtOAc (4 ml x 3). The organic fractions were combined, dried over magnesium sulphate, filtered and concentrated under reduced pressure to give a clear oil (17 mg) Chiral HPLC analysis of this showed an ee of 70%.

mnr26-1 15EtOH 05mL_120412.pdf

mnr30-2_filter_xstals.pdf
Attached Files
mnr26-1 15EtOH 05mL_120412.pdf
mnr30-2_filter_xstals.pdf
mnr26-1_110412.pdf
mnr26-1_110412.pdf
mnr30-2_firstfilter.pdf