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7th June 2010 @ 14:27
Preparation of the ‘Ugi intermediate’ of (MeO)2-PZQ as starting material for the Pictet-Spengler cyclisation – upscaling of MW32-1

Reaction Scheme1


Start time: 11:25 PM 07/06/2010
End time: 10:15 AM 08/06/2010

To a solution of MW14-3 (500 mg, 1.53 mmol) and Et3N (233 mg, 2.30 mmol) in DCM (10 mL) was added of cyclohexanecarboxylic acid chloride (247 mg, 1.69 mmol) at 0°C, warmed to room temperature and stirred for 18 h.
- after 2 h: TLC (EA = 100%, stain: ceric ammonium molybdate, Rf = 0.33) still some starting material

Work-up: quenched with water, extracted with DCM, washed with aq. ammonium chloride, dried over sodium sulfate, concentrated.
Purification by column chromatography (EA, 100%)

Product MW32-3: pale yellow high-viscous oil 629 mg (1.43 mmol, 93%)
1H NMR: Trace amounts of solvents (DCM) --> high vacuum

Analytical data:
-> see MW40-1
Attached Files
Reaction Scheme1
1H NMR MW32-3