Pictet-Spengler route to Praziquantel

 

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Summary and Conclusion
Scale up of KAB19-1 in the preparing of more starting material for further experiments. Reaction went as expected.
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START: 21/03/12
FINISH: 21/03/12




Hazard and Risk Assessment
As for KAB19-1 (here)

Previous Experiments
Synthesis of N-[2-(3,4-Dimethoxyphenyl)ethyl]-1-phenylmethanimine (KAB19-1)
Synthesis of N-benzylidene-N-phenethylamine (KAB18-2)

Following Experiments


Chemical Information
3,4-Dimethoxyphenethylamine (1) - SMILES: O(c1ccc(cc1OC)CCN)C, InChI: InChI=1S/C10H15NO2/c1-12-9-4-3-8(5-6-11)7-10(9)13-2/h3-4,7H,5-6,11H2,1-2H3, InChIKey: ANOUKFYBOAKOIR-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-[2-(3,4-Dimethoxyphenyl)ethyl]-1-phenylmethanimine (3, KAB19-2) SMILES: O(c1ccc(cc1OC)CC/N=C/c2ccccc2)C, InChI: InChI=1S/C17H19NO2/c1-19-16-9-8-14(12-17(16)20-2)10-11-18-13-15-6-4-3-5-7-15/h3-9,12-13H,10-11H2,1-2H3/b18-13+, InChIKey: HEYKSOUNCDDROU-QGOAFFKASA-N

Procedure
Benzaldehyde (3.1 mL, 30 mmol, 1 eq) was added to diethyl ether (10 mL) before the addition of 3,4-dimethoxyphenethylamine (5.0 mL, 30 mmol, 1 eq). The reaction mixture was left to stir at rt for 5 hours. The reaction mixture was then diluted with diethyl ether (20 mL), dried over magnesium sulfate, filtered and concentrated under reduced pressure to give KAB19-2 as a yellow oil (7.34 g, 90%).

Summary and Conclusion
Scale up of KAB19-1 in the preparing of more starting material for further experiments. Reaction went as expected.

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NOTES
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