All Notebooks | Help | Support | About
18th March 2012 @ 22:21
=====================================================
Summary and Conclusion
KAB19-1 did not cyclise to form the substituted tetrahydroisoquinoline (KAB21-1) when stirred in neat methanesulfonic acid for 3.5 hours. Starting material was obtained.
=====================================================

START: 9:45, 19/03/12
FINISH: 19/03/12

Scheme%20KAB21-1.png

Hazard and Risk Assessment
Hazard and Risk Assessment KAB21-1


Previous Experiments
Synthesis of N-[2-(3,4-Dimethoxyphenyl)ethyl]-1-phenylmethanimine (KAB19-1)
Synthesis of 1-phenyl-1,2,3,4-tetrahydroisoquinoline (KAB20-2)
Synthesis of 1-phenyl-1,2,3,4-tetrahydroisoquinoline (KAB20-3)

Following Experiments

Chemical Information
N-[2-(3,4-Dimethoxyphenyl)ethyl]-1-phenylmethanimine (1, KAB19-1) 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
6,7-Dimethoxy-1-phenyl-1,2,3,4-tetrahydroisoquinoline (2, KAB21-1) - SMILES: O(c1c(OC)cc3c(c1)C(c2ccccc2)NCC3)C, InChI: InChI=1S/C17H19NO2/c1-19-15-10-13-8-9-18-17(12-6-4-3-5-7-12)14(13)11-16(15)20-2/h3-7,10-11,17-18H,8-9H2,1-2H3, InChIKey: GZGZWZVAJDFXJK-UHFFFAOYSA-N

Procedure
KAB19-1 (418 mg, 1.55 mmol, 1 eq) was dissolved in toluene (40 mL) before the addition of methanesulfonic acid (0.1 mL, 1.6 mmol, 1 eq) at 0 °C. The reaction mixture was allowed to warm to rt and left to stir from 9:45.
After 3.5 hours the reaction mixture was diluted with EtOAc (50 mL), then quenched with saturated sodium bicarbonate solution (50 mL). The organic fraction was separated and the basic aqueous layer was extracted with EtOAc (2 × 50 mL). The organic layers were combined, dried over magnesium sulfate, filtered, then concentrated under reduced pressure to give crude KAB21-1 as a yellow oil.

1H-NMR of the product indicated the isolated material was the KAB19-1 starting material.
Raw H-NMR crude KAB21-1

Product taken no further.

Summary and Conclusion
KAB19-1 did not cyclise to form the substituted tetrahydroisoquinoline (KAB21-1) when stirred in neat methanesulfonic acid for 3.5 hours. Starting material was obtained.

-----------------------------------------------------------------------------
NOTES 19/03/12
- No product formed. Got starting material back. Heat next time.
-----------------------------------------------------------------------------
Linked Posts
Attached Files
Scheme KAB21-1
Hazard and Risk Assessment KAB21-1
Raw H-NMR crude KAB21-1