Pictet-Spengler route to Praziquantel

 

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Summary and Conclusion
Reaction went as expected to give the KAB18-2 product. Yield for the reaction was 8.3 g.
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START: 21/03/12
FINISH: 21/03/12

Preparing more KAB18 starting material.




Hazard and Risk Assessment
As for KAB18-1 (here).

Previous Experiments
Synthesis of N-benzylidene-N-phenethylamine (KAB18-1)

Following Experiments


Chemical Information
2-Phenethylamine (1) - SMILES: c1ccc(cc1)CCN, InChI: InChI=1S/C8H11N/c9-7-6-8-4-2-1-3-5-8/h1-5H,6-7,9H2, InChIKey: BHHGXPLMPWCGHP-UHFFFAOYSA-N.
Benzaldehyde (2)- SMILES: c1ccc(cc1)C=O, InChI: InChI=1S/C7H6O/c8-6-7-4-2-1-3-5-7/h1-6H, InChIKey: HUMNYLRZRPPJDN-UHFFFAOYSA-N.
N-Benzylidene-N-phenethylamine (3, KAB18-2) - SMILES: N(=C/c1ccccc1)\CCc2ccccc2, InChI: InChI=1S/C15H15N/c1-3-7-14(8-4-1)11-12-16-13-15-9-5-2-6-10-15/h1-10,13H,11-12H2/b16-13+, InChIKey: OOBAKFDIGIHHOM-DTQAZKPQSA-N

Procedure
Benzaldehyde (4 mL, 40 mmol, 1 eq) was added to stirring diethyl ether (10 mL) before the addition of 2-phenethylamine (5 mL, 40 mmol, 1 eq). The reaction mixture was left to stir at rt for 5 hours then dried over magnesium sulfate, filtered and concentrated under reduced pressure to give KAB18-2 as a yellow solid in quantitative yield (8.3 g).

Summary and Conclusion
Reaction went as expected to give the KAB18-2 product. Yield for the reaction was 8.3 g.