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20th March 2012 @ 22:50
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Summary and Conclusion
Formation of the KAB22-1 product was facile and clean. Yield was quantitative. Suggest concentration of the reaction mixture once the needles have formed rather than attempting filtration.
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START: 21/03/12
FINISH: 21/03/12

Background
See synaptic leap post: here.




Hazard and Risk Assessment
Hazard and Risk Assessment KAB22-1


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

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.
4-Nitrobenzaldehyde (2)- SMILES: O=C([H])C1=CC=C([N+]([O-])=O)C=C1, InChI: InChI=1S/C7H5NO3/c9-5-6-1-3-7(4-2-6)8(10)11/h1-5H, InChIKey: BXRFQSNOROATLV-UHFFFAOYSA-N.
N-(4-nitrobenzylidene)-2-phenylethanamine (3, KAB22-1) - SMILES: O=[N+]([O-])C1=CC=C(/C=N/CCC2=CC=CC=C2)C=C1, InChI: InChI=1S/C15H14N2O2/c18-17(19)15-8-6-14(7-9-15)12-16-11-10-13-4-2-1-3-5-13/h1-9,12H,10-11H2/b16-12-, InChIKey: VVVXMEABOODTDX-VBKFSLOCSA-N

Procedure
Phenethylamine (5.0 mL, 40 mmol, 1 eq) was slowly added to a stirring suspension of 4-nitrobenzaldehyde (6.0 g, 40 mmol, 1 eq) in diethyl ether (40 mL). The 4-nitrobenzaldehyde solid was visibly consumed as the phenethylamine was added, turning the solution a deep orange colour. The reaction mixture was stirred at rt for 1 hour before a yellowish solid precipitated out.
Reaction mixture (~1 h)

An attempt to filter the solid failed. The filtrate and residual solid were dissolved in excess Et2O then concentrated under reduced pressure. A yellow solid crystallised out of the concentrated solution and the residual solvent was removed under a high vacuum. 1H-NMR confirmed the pale yellow needles as the KAB22-1 product, which was obtained in quantitative yield (10.1 g).
KAB22-1
H-NMR KAB22-1
Raw H-NMR KAB22-1


Summary and Conclusion
Formation of the KAB22-1 product was facile and clean. Yield was quantitative. Suggest concentration of the reaction mixture once the needles have formed rather than attempting filtration.

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NOTES 21/03/12
- 4-nitrobenzaldehyde is poorly soluble (or insoluble) in Et2O.
- Product soluble in diethyl ether. Crystallisation probably due to saturation of the ether with product.
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Linked Posts
Attached Files
Scheme KAB22-1
Table KAB22-1
Hazard and Risk Assessment KAB22-1
H-NMR KAB22-1
Raw H-NMR KAB22-1
Reaction mixture (~1 h)
KAB22-1
Scheme KAB22-1