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Lego
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| Joined: 15 Apr 2005 |
| Posts: 55 |
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2506.80 Points
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2C-X precursor from benzene in two simple steps
Sun Jul 03, 2005 3:38 am |
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This patent has been posted at the Hive a long time ago, but Lego was reminded about it, inspired by the thread:
US4046652
http://v3.espacenet.com/textdoc?DB=EPODOC&IDX=US4046652&F=0
In Synthesis, 1979, 8, 603-605 and Synthesis, 1979, 8, 605-607 the reduction of the acetals to the corresponding 1,4-dimethoxybenzenes is described. Legos has the scanned articles, so the can bee requested. If the acetals are dissolved in ether and dry HCl is added 2,5-dimethoxy-1-chlorobenzene is formed in very good yields (88%), workup is simple distillation. Thiols can also bee used for 2C-T-X precursors.
This method seems to be very practical as it does not need any watched chemicals and a bee could get a methylated precursor without a methylating agent. Anybee who is willed to try this has full psychological support from Lego! |
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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: 2C-X precursor from benzene in two simple steps
Sun Jul 03, 2005 3:02 pm |
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This procedure is interesting, however something bothers me. How is an average bee supposed to construct an electrolitical cell like the one in the patent? What could be used as replacement for the porous polyethylene tissue paper? Things like that always prevent me from being interested in further exploration of such procedures. On the other hand electrochemical oxidations are often the most eco-friendly and clean ways to get to certain compounds.
Do you have any idea how would one get from 1-chloro-2,5-dimethoxybenzene to 2C-C/DOC? |
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PSY420
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| Joined: 30 Jun 2005 |
| Posts: 30 |
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1174.16 Points
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re: 2C-X precursor from benzene in two simple steps
Sun Jul 03, 2005 3:26 pm |
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You wouldn't even have to:
1 : Synthesis, 605-607 (1979)
2 : Collect. Czech. Chem. Commun.; EN; 55; 3; 1990; 782-796
Unfortunately I didn't already get those articles, of which I think the second one is extremely interesting, 2C-T's are beyond the scope of my current research... yet.
--PSY420-- |
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Lego
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| Joined: 15 Apr 2005 |
| Posts: 55 |
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2506.80 Points
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Re: re: 2C-X precursor from benzene in two simple steps
Sun Jul 03, 2005 4:33 pm |
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| demorol wrote: |
This procedure is interesting, however something bothers me. How is an average bee supposed to construct an electrolitical cell like the one in the patent? What could be used as replacement for the porous polyethylene tissue paper? Things like that always prevent me from being interested in further exploration of such procedures. On the other hand electrochemical oxidations are often the most eco-friendly and clean ways to get to certain compounds.
Do you have any idea how would one get from 1-chloro-2,5-dimethoxybenzene to 2C-C/DOC?
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Lego also considered electro chemistry as a great, but impractical method for bees until she read the story about the successful reduction of P2NP to amphetamine via electro chemistry. It is not as complicated as it sound first. A FOF was using a flower pot as a cell divider for electro chemistry experiments with good results. Electro chemistry equipments are not too expensive in aquisition and fucking cheap in use as they work a real long time.
How to get to 2C-X from this precursor:
2-Chloro-1,4-dimethoxybenzene --> 4-Chloro-2,5-dimethoxybenzaldehyde
Reagent: Trifluoroacetic acid, hexamethylentetramine
Yield: 75%
Time: 12 h
Ref: J. Org. Chem., 1993, 58(27), 7906-7912
2,5-Dimethoxyfluorobenzene --> 2,5-dimethoxy-4-fluorobenzaldehyde
Reagent: dichloro-methoxy-methane (dichloromethylmethylether); SnCl4
Ref: J. Med. Chem., 1982, 25(10), 1163-1168
2-Bromo-1,4-dimethoxybenzene --> 1-bromo-4-chloromethyl-2,5-dimethoxy-benzene
Reagent: formaldehyde; HCl
Ref: Bull. Soc. Chim. Fr., 1953, C46
2-Chloro-1,4-dimethoxybenzene --> 1-chloro-4-iodo-2,5-dimethoxybenzene
Reagent: ICl (iodine monochloride); acetic acid
Ref: Acta. Chem. Scand., 1958, 12, 537&542
2-Chloro-1,4-dimethoxybenzene --> 1-chloro-4-iodo-2,5-dimethoxybenzene
Reagent: iodine; HgO; ultrasound
Yield: 52%
Ref: Eur. J. Org. Chem., 1998, 2, 335-348
2-Bromo-1,4-dimethoxybenzene --> 2-allyl-1,4-dimethoxybenzene (2,5-dimethoxyallylbenzene)
Reagent: 3-bromo-propene (allylbromide); n-BuLi; Cu2 I2
Ref: J. Org. Chem., 1980, 45(3), 378-384
2-Bromo-1,4-dimethoxybenzene --> 2,5-dimethoxyphenylacetonitrile
Reagent: Acetonitrile; KNH2 ; liquid NH3
Ref: J. Org. Chem., 1985, 50(8 ), 1334-1337
Benzaldehydes can bee obtained from bromobenzenes via the grignard reagent and sodium formiate.
From iodobenzenes it is possible to get to the corresponding P2P by reaction with acetylacetone and CuI. The experimental details are somewhere lost in the Hive. |
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Vitus
Psychoscientist
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| Joined: 19 Apr 2005 |
| Posts: 72 |
| Location: Dunwich |
2608.18 Points
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re: 2C-X precursor from benzene in two simple steps
Sun Jul 03, 2005 5:14 pm |
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More electrolysis refs:
Anodic oxidation of 1,4-dimethoxybenzene in basic methanol yields 3,3,6,6-tetramethoxycyclohexa-1,4-diene in good yield.
using KOH: J. Am. Chem. Soc. 85 (1963) 2525-26
KOH, 73% yield: J. Org. Chem. 56, 21 (1991) 6156
KOH, 98% yield: Synth. Commun. 24, 20 (1994) 2989
KOH: Justus Liebig's Ann. Chem. (1977) 1807-1816
2% KOH, 1.5V, 1A: J. Org. Chem. 62, 26 (1997) 9128-9137
These might also be of interest:
J. Chem. Soc. Perkin Trans. 1 11 (1990) 2979-2988
Tetrahedron 29 (1973) 279-284
J. Chem. Soc. Perkin Trans. 1 (1978) 696-707
An. Quim. 74 (1978) 954
Org. Syn. 57 (1977) 92 |
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Lego
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| Joined: 15 Apr 2005 |
| Posts: 55 |
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2506.80 Points
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Re: re: 2C-X precursor from benzene in two simple steps
Sun Jul 03, 2005 7:03 pm |
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Yes, that's true? But what's the use?
If one has 1,4-dimethoxybenzene one can brominate it and needs one step less and no electro chemistry equipment.
| Vitus wrote: |
More electrolysis refs:
Anodic oxidation of 1,4-dimethoxybenzene in basic methanol yields 3,3,6,6-tetramethoxycyclohexa-1,4-diene in good yield.
using KOH: J. Am. Chem. Soc. 85 (1963) 2525-26
KOH, 73% yield: J. Org. Chem. 56, 21 (1991) 6156
KOH, 98% yield: Synth. Commun. 24, 20 (1994) 2989
KOH: Justus Liebig's Ann. Chem. (1977) 1807-1816
2% KOH, 1.5V, 1A: J. Org. Chem. 62, 26 (1997) 9128-9137
These might also be of interest:
J. Chem. Soc. Perkin Trans. 1 11 (1990) 2979-2988
Tetrahedron 29 (1973) 279-284
J. Chem. Soc. Perkin Trans. 1 (1978) 696-707
An. Quim. 74 (1978) 954
Org. Syn. 57 (1977) 92
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Vitus
Psychoscientist
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| Joined: 19 Apr 2005 |
| Posts: 72 |
| Location: Dunwich |
2608.18 Points
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re: 2C-X precursor from benzene in two simple steps
Sun Jul 03, 2005 7:32 pm |
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There is always a use. For example if I'd be interested in the procedure PSY420 mentioned above to make 2,5-dimethoxy-ethylthiobenzene, there is a choice between bromination followed by swap w ethanethiol, and electrolysis.
What, for example, if one ran out of bromine or bromide salts, but has a power supply and is aching to make some of this substituted benzene? 
Hey, it is always nice to have many practical usable roads available. |
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Lego
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| Joined: 15 Apr 2005 |
| Posts: 55 |
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2506.80 Points
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Re: re: 2C-X precursor from benzene in two simple steps
Mon Jul 04, 2005 3:19 am |
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| Vitus wrote: |
There is always a use. For example if I'd be interested in the procedure PSY420 mentioned above to make 2,5-dimethoxy-ethylthiobenzene, there is a choice between bromination followed by swap w ethanethiol, and electrolysis.
What, for example, if one ran out of bromine or bromide salts, but has a power supply and is aching to make some of this substituted benzene?
Hey, it is always nice to have many practical usable roads available.
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Yes, you are right it was not meant offending. The power of literature search is to offer as many possibilities as possible for the chemist. |
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