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6th February 2012 @ 02:42
Mnr: 21-30
Small scale reaction to test optical purity of the starting MNR3-3 as chiral HPLC can't separate the two.

MNR24-1%20scheme.png

mnr24-1%20table.PNG

Hazard and Risk Assessment:

To a cooled solution of R-(+)Praziquanamine (MNR3-3, mmol) in DCM (5 mL) at 0°C was added triethylamine (0.21 mL, 1.48 mmol) and benzoyl chloride(0.13 mL, 1.09 mmol). The solution was stirred overnight at room temperature.

The solution was quenched with water (5 mL) and stirred for a further 30 min. The layers were separated and the organic layer was washed with saturated sodium carbonate solution (5 mL), 0.5 M HCl (5 mL) and brine (5 mL). Dried over magnesium sulfate, filtered and concentrated under reduced pressure.

Crude:- 0.341 g

Column:- 50-100 % EtOAc/Hex

frac 9-13 0.237 g, 0.759 mmol, 77% as white crystals

Characterisation

mnr24-1_1H.pdf
mnr24-1_frac9-13.zip


1H NMR (500 MHz, CDCl3): d= 7. 35-7.41 (m, 5H), 7.29-7.15 (m, 4H), 5,25 (br, 1H), 4.99 (br, 1H), 4.81 (br, 1H), 4.36 (br, 1H), 4.09 (br, 1H), 3.07 (br, 1H), 3.03-2.93 (m, 1H), 2.93-2.84 (m, 1H), 2.83-2.73 (m, 1H).

Chiral HPLC

80:20:0.2 IPA:Hexane:TEA
flow rate 0.35 mL per minute

96.4 % ee

Chiral HPLC mnr24-1

Chiral HPLC MW58

Melting point 119-121 °C
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Attached Files
mnr24-1 table.PNG
MNR24-1 scheme.png
mnr24-1.pdf
mnr_mw58.pdf
HPLC-MNR14.pdf
mnr24-1_frac9-13.zip
mnr24-1_1H.pdf