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brain
Linguist Extraordinaire
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| Joined: 08 Mar 2005 |
| Posts: 143 |
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2405.16 Points
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2,5-metoxybenzaldehyde from p-metoxyphenol?
Mon Apr 11, 2005 1:02 am |
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| can anyone help me? how to obtain that with good yelds? |
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IndoleAmine
Dreamreader Deluxe
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| Joined: 09 Feb 2005 |
| Posts: 681 |
| Location: Bahamas |
18717.10 Points
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Mon Apr 11, 2005 1:15 am |
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Reimer-tiemann formylation with CHCl3 gives 2-OH-5-MeO-benzaldehyde (?), methylation with MeI or dimethyl sulfate gives 2,5-dimethoxybenzaldehyde.
Messy process though.
(check your mail!  )
i_a |
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jory
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| Joined: 22 Apr 2005 |
| Posts: 20 |
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661.50 Points
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Re: 2,5-metoxybenzaldehyde from p-metoxyphenol?
Mon Apr 25, 2005 11:26 pm |
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| brain wrote: |
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can anyone help me? how to obtain that with good yelds?
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i thing that better may be using hydroquinone HO-Ph-OH (from fotosupply or oxidation of aniline with K2Cr2O7), formylation eq. with CHCl3, next (CH3)2SO4 (DMF, K2CO3). |
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demorol
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| Joined: 17 Feb 2005 |
| Posts: 14 |
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344.82 Points
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Re: 2,5-metoxybenzaldehyde from p-metoxyphenol?
Tue Apr 26, 2005 9:46 pm |
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| jory wrote: |
| brain wrote: |
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can anyone help me? how to obtain that with good yelds?
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i thing that better may be using hydroquinone HO-Ph-OH (from fotosupply or oxidation of aniline with K2Cr2O7), formylation eq. with CHCl3, next (CH3)2SO4 (DMF, K2CO3).
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Yields are shitty with your procedure. Use Reimer-Tiemann or better, Mg-orthoformylation. Reimer-Tiemann isn't that messy when you get ahold of it. |
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IndoleAmine
Dreamreader Deluxe
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| Joined: 09 Feb 2005 |
| Posts: 681 |
| Location: Bahamas |
18717.10 Points
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Tue Apr 26, 2005 10:10 pm |
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And p-methoxyphenol is already halfway methylated compared to hydroquinone, so chances for tar formation are reduced by 50% statistically speaking..  |
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jory
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| Joined: 22 Apr 2005 |
| Posts: 20 |
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661.50 Points
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Re: 2,5-metoxybenzaldehyde from p-metoxyphenol?
Tue Apr 26, 2005 11:17 pm |
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| demorol wrote: |
| jory wrote: |
| brain wrote: |
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can anyone help me? how to obtain that with good yelds?
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i thing that better may be using hydroquinone HO-Ph-OH (from fotosupply or oxidation of aniline with K2Cr2O7), formylation eq. with CHCl3, next (CH3)2SO4 (DMF, K2CO3).
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Yields are shitty with your procedure. Use Reimer-Tiemann or better, Mg-orthoformylation. Reimer-Tiemann isn't that messy when you get ahold of it.
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RHODIUM/chemistry/formylations.html sound good ever for hydroquinone |
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