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24th January 2011 @ 06:58
Preparation of starting material for a scaled-up racemic resolution of PZQamine

See: Hydrolysis of rac-PZQ (MW2-13)
Following the optimized conditions for rac-PZQ: see Optimizing the acid cleavage conditions II



Hazard and Risk Assessment:
Data: HIRAC MW2

Start time: 6:30 PM 24/01/2011
End time: 8:50 AM 25/01/2011

Procedure:
rac-PZQ (20.0 g, 64.0 mmol) was dissolved in a mixture of EtOH (150 mL) and 1N HCl (600 mL, 53.0 mL of 11.3 N HCl solution (35%) in 547 mL water) and heated to reflux for 14 h. Reaction monitored by TLC showed a complete consumption of PZQ (TLC, EA/hexane 1:1, Rf = 0.15 for PZQ).

Work-up:
Solution was cooled to room temperature, washed with EtOAc (4 times 15 mL), basified with NaOH solution (5 N) to ph 12, extracted with DCM (5 x 30 mL), washed with brine, dried over NaSO4, evaporated under reduced pressure.
pale yellow oil turned into a solid after freezing the oil with liquid nitrogen under high vac and warmed to room temperature.

Yield:
11.1 g (52.0 mmol, 86%) pale yellow solid
[M.W. = 202.1 g/mol]
m.p. = 116.5 - 118.5°C
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