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6th February 2012 @ 02:44
Mnr: 21-30

Small scale reaction to test optical purity of the starting MNR2-4 as chiral HPLC can't separate the two enantiomers.

Hazard and Risk Assessment:

To a cooled solution of S-(-)Praziquanamine (MNR2-4, mmol) in DCM (5 mL) at 0°C was added triethylamine (0.21 mL, mol) 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:- 0.408 g

Column:- 50-100 % EtOAc/Hex

Frac 10-16, 0.259 g, 0.829 mmol, 84%

Characterisation

1H NMR (500 MHz, CDCl3): d= 7. 53-7.41 (m, 5H), 7.28-7.16 (m, 4H), 5,24 (br, 1H), 4.97 (br, 1H), 4.82 (br, 1H), 4.36 (br, 1H), 4.17-3.94 (m, 1H), 3.07 (br, 1H), 3.04-2.94 (m, 1H), 2.94-2.84 (m, 1H), 2.84-2.72 (m, 1H).

Chiral HPLC

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

100 % ee

Chiral HPLC mnr25-1

Chiral HPLC MW58

Melting point 122-123 °C

 

LRMS 

HRMS 

IR 

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