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Neo Retro
Старый Юный Химик
 Apr 28 2006, 17:05
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Both of these patents disclose processes for making propenylbenzenes via a propiophenone intermediate. The propiophenone derivative is reduced to a 1-propanol derivative and then dehydrated using azeotropic distillation.
Patent US6590127 Process for the preparation of pharmacologically active alpha-asarone from toxic beta-asarone rich acorus calamus oil
2,4,5-triMeO-propiophenone --> 1-propanol derivative and dehydration (examples V and VI)
& a lot of interesting references
Patent US6342613 Process for the synthesis of 5-(.alpha.-hydroxyalkyl) benzo[1,3]dioxols
5-propanoylbenzo[1,3]dioxol reduction to 1-propanol derivative and dehydration
(examples 3 and 5)
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милицыя
Повелитель мух
Apr 28 2006, 17:52
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Neo Retro thanks for your help again! 
you're really strong at digging up those drug patents
the dehydration of phenyl-1-propyl alcohol with toluenesulphonic acid was described in rhodium archieve but I never saw the original procedure. this patent rocks!
I only hope benzenesulphonic acid can do the same...
as for second one - I looked it through briefly -
the main synthesis is a bit too long (i think there are a better ways of alkylating the dioxole) but
there's described a GREAT and profitable way of making benzodioxol!!
those of us who don't buy the dioxol from chem suppliers,
usually expend a lot of solvents or a precious PTC to make it. the above procedure allows recovery a solvent, doesn't require a PTC and offers a quantitative yield and it's only disadvantage is the slow rm workup - steam distillation will take a whole day for 100g of dioxol (that's more than 600 mls of distillate). I will try as soon, as I get my hands on my DMF... it awaits me in the hideout, and I cant get it now cause I have no transport
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Neo Retro
Старый Юный Химик
May 2 2006, 03:18
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Yep, its surprising what you can find in the patent literature. Check out these patents, a one step tube furnace type reaction from aryl alkyl ketones to styrenes.
Patent US2482207 Process for making styrene and substituted styrenes
high temperature catalyst, EtOH + acetophenone
Patent US2482208 Process for making styrene and its derivatives
------------------
Here's some patents I found on aluminum isopropoxide reduction.
Patent US2098206 Manufacture of alcohols
Al isopropoxide reduction
Patent US2376817 Reduction of ketaldones
Al isopropoxide reduction w/ assisting agent
Patent US2394848 Process for the production of aliphatic alcohols
Al isopropoxide preparation details
Patent US2465486 Preparation of 4, 4'-divinyl-biphenyl
4,4'-diacetyl-biphenyl reduced to 4,4'-di-(a-hydroxyethyl)-biphenyl with the aid of aluminum isopropoxide
high temperature dehydration with alumina or other dehydrating agent
Patent US2496067 Biphenyl derivatives and method of preparing them
4,4'-tetrachloro-4,4'-diacetyl-biphenyl reduced with aluminum isopropoxide in isopropyl alcohol (example 3)
This patent says the Al + ROH reaction is exothermic and has to be controlled by adding small amounts of metal at a time.
Patent US2965663
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MoonLight
Юный Химик
May 2 2006, 08:19
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I just hope noone forgot that it was possible to convert aryl ethyl ketones straight to propenylbenzenes via 'incomplete' Clemmensen reduction with Zn/HgCl2, as posted on The Hive by Regis:
Regis
(Stranger)
09-28-02 01:37
No 361260
Internal aryl alkenes from aryl ketones (WOW!)
(Rated as: excellent) Bookmark Reply
Taken from Synthetic Communications, 26 (14), 2625-2531 (1996)
Here's a way to reduce aryl ketones (easily synthesized by way of the Friedel-Crafts acylation reaction) to internal aryl alkenes.
Experimental:
Reduction of 1-Phenyl-butanone. This procedure was used for all reactions reported in the table. In a round bottom flask were placed 10.11 g (0.155 mol) of Zn dust, 0.498 g (1.84 mmol) of HgCl2, 10 mL of H2O, 0.5 mL of conc HCl, and a stir bar. After 10 min of stirring, the liquid was decanted, and any lumps were broken up with a spatula. To the flask were added 20 mL of 88% formic acid, 6 mL of 95% ethanol, and 2.0 mL (13.78 mmol) of 1-phenyl-1-butanone. The mixture was refluxed and stirred for 1 h. The liquid was decanted into a separatory funnel, and the residue stirred with 20 mL of H2O for 5 min. The water was also added to the separatory funnel and the residue stirred with 20 mL of CH2Cl2 for 5 min. The CH2Cl2 was used to extract the aqueous phase. The residue was washed two more times with 20 mL each of CH2Cl2, and the CH2Cl2 was used to extract the aqueous phase each time. The combined CH2Cl2 solution was washed with 1 N NaOH until the wash was basic (60 mL and 30 mL) and with sat. NaCl solution (60 mL) and dried over MgSO4. After filtration and solvent removal, the residue was distilled using a Kugelrohr apparatus to give 1.46 g of product (80% yield based on the molecular weight of the alkene) (bath temp 113-121 C at 43 torr). The IR and NMR spectra were a good match for that of trans-1-phenyl-1-butene, and the NMR spectrum also showed peaks indicative of the presence of small amounts of cis-1-phenyl-1-butene, butylbenzene, and CH2Cl2. Analysis by GC (10% Carbowax 20M) showed significant peaks at 0.54 min (1.3%), 1.7 min (7.2%), 2.3 min (10.1%), 3.4 min (80.5%). The peaks at 0.54, 1.7, and 3.4 min correspond tothe retention times of CH3Cl2, butylbenzene, and trans-1-phenyl-1-butene, respectively. The peaks at 2.3 and 3.4 min were collected by preparative GC. The NMR of the peak at 2.3 min agreed eith that reported for cis-1-phenyl-1-butene, and the NMR of the peak at 3.4 min matched that of trans-1-phenyl-1-butene.
Here are the some of the more interesting segments of the article:
"Our modification of the Clemmensen procedure which gives the highest ratio of alkene to alkane and the highest isolated yields involves refluxing the ketone with amalgamated zinc in 88% formic acid and 95% ethanol for 1 h. Significant results are summarized in the Table. Acetic acid could be used in place of formic acid, but replacement of phosphoric acid, ammonium chloride, or anilinium chloride resulted in a lower ratio of alkene or a very slow reaction. Methanol as the cosolvent was about as effective as ethanol, but cylcohexane, benzene, t-butyl alcohol, dioxane, or no cosolvent gave a slightly lower ratio of alkene. Zinc amalgamated in the usual manner was used for extraction during the work-up was used for most experiments and gave the best results. When methylene chloride was used for extraction during the work-up instead of diethyl ether, the isolated yields were improved significantly.
"1-Phenyl-2-propanone and 2-octanone, both alkyl ketones, did not react appreciably under the mild conditions used for aromatic ketones. 1-Phenyl-1-ethanone was reduced to a 16:84 GC ratio of ehtyl benzene to styrene but a distilled yield of only 19% was obtained. A H NMR of the undistilled sample showed the presence of a cyclopropyl group which is believed to be formed from a zinc-carbene intermediate (Zn=C) reacting with the alkene.
"Rearrangement of the same zinc-carbene intermediate accounts for eh formation of the alkene. Under the milder Clemmensen reduction conditions used here, apparantly aryl ketones easily form the zinc-carbene intermediate, and rearrangement to the alken is normally the major reaction pathway."
Yeilds for valerophenone were 80.6% of the trans isomer and 10.1% of the cis isomer (80% overall yield)
I hope I interpreted this part right (in regard to the cis and trans thing):
Yields for propiophenone were 78.2% of the trans isomer and 13.5% of the cis isomer (80% overall yield)
There's more interesting stuff about the standard Clemmensen reduction but my hands are tired of typing.
That's all for now, folks!!!
Русскоязычная версия этого документа на Юном Химике:
https://www.hyperlab.info/chemistry/synthes...en_modified.htm
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Neo Retro
Старый Юный Химик
May 2 2006, 19:47
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Check out the information foxy2 found here:
Phenylpropanol Dehydration
https://the-hive.archive.erowid.org/forum/showflat.pl?Cat=&Number=204087&part=all&vc=1
Это сообщение отредактировал namgramk - May 1 2018, 19:44
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MoonLight
Юный Химик
May 4 2006, 12:43
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Shhhit, will i ever stop experiencing this heart-breaking feeling when hearing of something 'posted on the Hive'? 
The point is not that i miss the site (although i do), but that the exploration of new areas in psychoactive chemistry died with it almost entirely 
Sure, it's nice to know that here we keep that spirit alive..... but still it's not the same without Rhodi and all the other guys
Sorry for offtopic.
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Neo Retro
Старый Юный Химик
May 5 2006, 16:15
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Here's a downloadable iso copy of the hive files. You have to unrar it.
HiveFilez-2005-04-08.rar (44848 KB)
http://rapidshare.de/files/13412429/HiveFilez-2005-04-08.rar.html
I also have daemontools for reading it offline. I have to figure out which file is the installation file.
I'm using DAEMON Tools 3.47. Here's a link for downloading it.
http://www.daemon-tools.cc/dtcc/download.php?mode=ViewCategory&catid=5
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Arsenik
Некто
Jun 4 2006, 23:22
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Speaking of arylketones...
Mona Hosseini Sarvari, Hashem Sharghi
Solvent-Free Catalytic Friedel-Crafts Acylation of Aromatic Compounds with Carboxylic Acids by Using a Novel Heterogeneous Catalyst System: p-Toluenesulfonic Acid/Graphite
Helv. Chim. Acta, 2005, 88(8), 2282-2287.
DOI: 10.1002/hlca.200590162
| цитата | Abstract
TsOH/graphite was found to be an effective catalyst system for the Friedel-Crafts acylation of aromatic compounds with carboxylic acids. Both aliphatic and aromatic carboxylic acids reacted smoothly under TsOH/graphite catalysis to afford the corresponding aromatic ketones in high yields. The graphite was easily recovered by simple extraction and could be reused without decrease of activity in the presence of fresh TsOH. |
Acylation of Aromatic Compounds, General Procedure: To a mixture of graphite (CAS No.7782-4 2-5; fine powder extra pure, from Merck; 0.3 g, 25 mmol) and anh. TsOH (0.03 g, 0.17 mmol) at 90 C in an oil bath the aromatic compound (1 mmol) and carboxylic acid (1 mmol) were added. The mixture was kept at 90 C while stirring with a mechanical stirrer for the time required to complete the reaction (see Table 2; TLC or GC monitoring). The solid mass (graphite) was then extracted with AcOEt (20 ml) and the AcOEt extract washed with aq.NaHCO3 soln., dried (Na2SO4) and evaporated: practically pure product. Yields are excellent.
Это сообщение отредактировал namgramk - May 1 2018, 19:54
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Neo Retro
Старый Юный Химик
Jun 4 2006, 23:57
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This should work with propionic acid in place of octanoic acid. Various organic sulfonic acids can be used as catalysts. Alkoxybenzenes work (see column 3 of the patent).
Patent US5041616 Preparation of aryl ketones
EXAMPLE 3
Hydroquinone (11.0 g, 0.1 mole), octanoic acid (30.2 g, 0.21 mole), heptane (110 mL), and methanesulfonic acid (10 mL, 0.14 mole) were heated at reflux (98.degree. C.) for 5 hours in a 300 mL flask equipped with a Dean-Stark trap. During this time, 3 mL of water was collected. The sulfonic acid layer was separated, and the heptane layer was washed once with 50 mL of water and twice with 50 mL portions of saturated, aqueous sodium bicarbonate solution. The mixture was filtered to remove 5 g of product, octanoylhydroquinone octanoate ester, while evaporation of the organic layer gave 17.3 g. The total yield of octanoylhydroquinone was 22.3 g, 94% of theory.
The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications may be effected within the spirit and scope of the invention.
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Arsenik
Некто
Jun 5 2006, 00:20
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I'm not sure whether that method really works, have anyone else done it?
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Neo Retro
Старый Юный Химик
Jun 6 2006, 01:08
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| цитата (сказал: Arsenik) ▲ | | I'm not sure whether that method really works, have anyone else done it? |
I never heard of anyone trying this. I recently found the patent.
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Arsenik
Некто
Jun 6 2006, 01:22
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| цитата (сказал: Neo Retro) ▲ | | I never heard of anyone trying this. I recently found the patent. |
check this:
AlCl3 and Md compounds, Chemistry Discourse, No. 346121
https://the-hive.archive.erowid.org/forum/showflat.pl?Cat=&Number=400120
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Neo Retro
Старый Юный Химик
Jun 7 2006, 02:13
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More interesting patents on styrenes.
Patent US3927133 Process for synthesizing styrene type compounds
heating compound formed from acetophenones/propiophenone and aluminum compounds (ie. aluminum isopropoxide)
Patent US3893948 Catalyst of reducing-dehydrating type for synthesizing vinylaromatic compounds and method of preparing it
ZnO/MgSO4/MgO reduction of diacetylbenzene
Patent US3439059 PROCESS FOR THE PRODUCTION OF DIVINYLBENZENES FROM DIACETYLBENZENES
MgO/MgSO4 catalyst, isopropanol, 240-400 degrees C
Patent US3153102 Process for the preparation of 1, 3, 5-trivinylbenzene
Patent US3375289 Method for preparation of divinylbenzenes
Patent US4783559 Process of reduction of aldehydes and ketones
alcohol and MOH
Patent US4054611 Method for the preparation of p-isopropenyl phenol
cleavage of bisphenols in solvent, ie. glycerine (table 1), 95+% yield
Patent US2560173 Condensation of alkyl aryl ethers with alpha-halogen alkanals
colum 4 lines 33+
We have observed that aryl alkyl ethers are far more reactive with alpha-halogen alkanals in the presence of sulfonic acid catalysts than chlorobenzene, and presumably, aromatic hydrocarbons. Thus, when a mixture of 0.1 mol of chloral, 0.2 mol of chlorobenzene and, 1.48 mols of pure methanesulfonic acid was heated at 70 to 130 C for six hours, no-DDT (111-trichloro- 2,2-bis(p-chlorophenyl) ethane) could be isolated from the reaction mixture and only a small quantity of black viscous oil was obtained besides the original reactants.
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Neo Retro
Старый Юный Химик
Jun 7 2006, 05:15
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This looks interesting. Alpha-alkylaminoacylophenones from propiophenones and methyl-N-bromo-amine (from methylamine and bromine).
Patent US2155194Присоединённые файлы
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Neo Retro
Старый Юный Химик
Jun 7 2006, 22:52
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Need translation of this Russian patent.
Patent SU643483
TITLE: 2,4-Dimethyl-styrene for plastic scintillator mfr. -
prepd. by redn. of 2,4-dimethyl-acetophenone with
aluminium isopropoxide in boiling toluene
ABSTRACT:
The cpd. is 2,4-dimethyl styrene (I). It is obtd. by redn. of
2,4-dimethyl-acetophenone (II) with aluminium iso-propoxide (III) (both reagents
in equimolar ratio) in a solvent, e.g. toluene (IV) and boiling the reaction
mixt. (2.5-3.0 hrs.). This is followed by a simultaneous, gradual temp. rise
to 165-170 degrees C, removal of the solvent by distn. (10-15 hrs). The final
prod. is isolated by double rectification in presence of an adsorbent
(aluminium oxide and activated carbon).
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Neo Retro
Старый Юный Химик
Jun 7 2006, 22:55
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More info on the synthesis of aluminum isopropoxide.
Patent US5142078 Aluminum alkoxide synthesis with titanium as a catalyst
column 1 line 1+
The synthesis of aluminum alkoxides from the metal using an alcohol
reagent and catalyst is known with the following references illustrating
various type of catalysts which might be used: U.S. Pat. Nos. 2,125,961 (use
of iodine as a catalyst); 2,579,251 (use of anhydrous cupric chloride as a
catalyst with the mention made of iodine, mercuric chloride, ferric chloride,
stannic chloride, and boron trioxide as prior art catalysts); 2,636,865 (use of
mercuric chloride as the catalyst); 2,666,076 (use of mercuric chloride, ferric
chloride, stannic chloride, cupric chloride, boron trioxide, or iodine as the
possible catalysts); and 4,745,204 (use of gallium and/or gallium based alloy).
In all of these syntheses, the catalyst will reside with the product aluminum
alkoxide as an impurity. This impurity will interfere with the utilization of
aluminum alkoxide as a precursor for such final products as ultra pure ceramics
for electronic applications and ultra pure alumina for laser grade powder.
Patent US2125961
Patent US2579251
Patent US2666076
Patent US4745204
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милицыя
Повелитель мух
Jun 9 2006, 17:02
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Оценено как: English to Русский
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here you go! Patent SU643483 on english
Invention realtes to preparation of vinyl-derivatives of aromatic hydrocabons, exactly the 2,4-dimethylstyrene.
The known method of styrene prep. is from 24-dimethylacetophenone, by reducing it to alcohol and dehydrating in presens of Al\Cr catalyst at 450-550C and pressure of 5-12 atmospheres. This method gives 32-48 conversion of initial compound with 76-82% selectivity.
The closest to patent method is the reduction of 24-dimethylacetophenone - by Al isopropoxide in boiling solvent media with following dehydration of produced alcohol in presence of KHSO4 and polymerisation inhibitor. However the quality of product made by the above method is unsatisfcatory. The use of common purification methods does't permit to obtain pure and translusent product. The target of this research is to simplify the production tech and increase the purity of the final compound. the target may be achieved by reduction of 24-dimethylacetophenone - by Al isopropoxide with equimolar ratio of reagents by 2?5-3 hour of reflux while gradually increasing rm temp to 165-175C, distilling the solvent during 10-15 hours and separation of final product by fractional distillation.... (this is somewhy repeated twice in different words)
experimental
2,4-dimethylacetophenone -
to a suspension of 156g anhydrous AlCl3 in 450 CCl4 with stirring there was added 82 mls of AcCl (distilled from AcOH previously). At 15-20C during 2 hours 123mls of m-xylene was dripped in. The rm was stired for further 2 hours and then 500 ml of cold 10% HCl is added. Organic layer separated, washed with H2O, with diluted NaOH and again with H2O until pH neutral. Solvents disstilled at atmospheric pressure, and the residue was vac. distilled (82 c at 1mm) Yield of 24dimethylacetophenone is 144,6g (95%).
2,4 dimethylstyrene
Al isopropoxide is prepared by refluxing 300 mls of dry isopropyl alcohol, 30 g of Al turnings and 5 g of HgCl2. to this fresh solution of Al isopropoxide is added 250 ml of dry toluene and 163 mls of dimethylacetophenone. The mix is refluxed for 2 hours while gradually increasing rm temp to 165-175C and then slowly distill off the solvents during 12 hours until distillate probe contains acetone and rm solidifies. The residue is cooled and diluted HCl (1 part conc HCl + 1 part H2O) is added. Organics extracted with ether, wash with H2O dry with Na2SO4 and distill at vacuum.
2,4 dimethylstyrene is obtained at 66C at 7mm - yield 75 ml (61%) and 35 mls of 24 dimethyphenyl-methylcarbinol 112C at 8mm.
For styrene purification it is twice distilled at vacuum under nitrogen whith 5% of aluminium oxide an 1% of activated carbon
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MoonLight
Юный Химик
Jun 9 2006, 19:07
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Клёво я Милицыин пост порейтил - с точностью до наоборот
Спасибо, кстати!
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милицыя
Повелитель мух
Jun 9 2006, 20:29
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MoonLight, ноу проблем! рад помочь
насчет патента - то что восстановление и дегидратация проходят в одну стадию это прикольно конечно, ( хотя для некоторых фенилпропанол является более доступным чем пропиофенон) - но это достигается 12-ю часами отгонки растворителя!. как это дело так сильно затянуть??? отгонять растовритель с дефлегматором?
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Neo Retro
Старый Юный Химик
Jun 10 2006, 16:39
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Thanks, милицыя. Looks like some of its converted into 2,4-dimethyphenyl-methylcarbinol.
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милицыя
Повелитель мух
Aug 3 2006, 15:24
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господа, скажите, как будет присоединяться метиламин из окиси-пропенилбензола?
окиси пропенилбензолов получаются из пропенилбензолов под действием ДМДО
количественно или c выходом 60-70% под действием перуксусной в ДХМ в присутствии NaHCO3 для связывания уксусной кислоты.
окись метилстирола легко перегоняется в водоструйном вакууме
окисление ДМДО стильбена, приводится таблица с выходами для других стиролов
окисление стильбена перуксусной к-той
и вот возник вопрос
PhCH(-O-)CHCH3 + MeNH2 + H2O =>
образуется PhCH(NHCH3)CH(OH)CH3 или PhCH(OH)CH(NHCH3)CH3 ?
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BlueSystem
Некто
Aug 4 2006, 05:09
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Будет так:
PhCH(-O-)CHCH3 + MeNH2 => PhCH(OH)CH(NHCH3)CH3
По аналогии получения, кажется, фетанола, мезатона, баметансульфата и др в Рубцове
OH-PhCH(-O-)CH2 + MeNH2 => OH-PhCH(OH)CH2-NHCH3
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милицыя
Повелитель мух
Aug 4 2006, 10:17
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спасибо, я эти примеры в рубцове смотрел, но там отличие -
у стирола один атом связаный а оксирановое кольцо вторичный (соседний с фенилом) а другой первичный, нуклеофильная частица (амин) идет к первичному атому, и окисное кольцо разрывается, оставляя кислород у более замещенного вторичного С.
"SN2 нуклеофильное замещение идет по наименее замещенному, пространственно более доступному атому углерода" -
а в случае пропенилбензола оба атома вторичные, так вот не будет образовываваться смесь продуктов с аминогруппой в 1 и 2 положениях?
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Neo Retro
Старый Юный Химик
Oct 9 2006, 05:07
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Some patents on the Fries rearrangement.
This looks interesting.
Patent US2763691 Process for production of 2,4,5-trihydroxyacetophenone
1,2,4-triacetoxybenzene -> 2,4,5-trihydroxyacetophenone
Patent US2763691 Process for production of 2,4,5-trihydroxyacetophenone
aromatic sulfonic acid catalyst, Fries rearrangement, quinone + acetic anhydride -> 1,2,4-triacetoxybenzene
quinone + propionic anhydride -> ?
Patent US2907794 Method for preparing polyhydroxyacetophenones
Patent US3354221 Production of phenols
Fries rearrangement, phenolic esters -> phenolic ketones
Patent US3098099 Ester-ketone conversion
Fries rearrangement w/ cationic exchange resin
Patent US2748160 Process for preparing 2,5-diacetoxystyrene and intermediates therefor
hydroquinone diacetate -> acetyl hydroquinone
Patent US3501519 ALPHA-SUBSTITUTED-(2,5-DIACYLOXYPHENYL) ACETALDEHYDE
Patent US3291798 Hydroquinones, lower alkanoyl derivatives thereof and processes for their production
Patent US3501519 ALPHA-SUBSTITUTED-(2,5-DIACYLOXYPHENYL) ACETALDEHYDE
Patent US3354221 Production of phenols
Fries rearrangement with aluminosilicate zeolite catalysts
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Neo Retro
Старый Юный Химик
Oct 9 2006, 20:41
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Note that propionic anhydride is List I in the USA.
Process for making propionic acid from methyl ethyl ketone.
https://www.erowid.org/archive/rhodium/chem...ionic.acid.html
Something else you can do with propionic acid:
| цитата |
There was added a solution of 74 g 2,5-dimethoxypropiophenone (from the reaction of propionic acid and p-dimethoxybenzene in the presence of polyphosphoric acid, see under DOAM for an effective general procedure) in 140 g EtOH.
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https://www.erowid.org/library/books_online...pihkal071.shtml
---------------------------------
Methods of making polyphosphoric acid
Patent US2493809 Manufacture of polyphosphates
Patent US3192013 Anhydrous liquid phosphoric acid
column 11 heating phosphoric acid -> polyphosphoric acid
Patent US3276510 Concentration of Phosphoric acid
Patent US3325244 Potassium pyrophosphate solution
column 2
(3)The solid is heated at 400' to 500' C. to drive off water of constitution,
thereby causing condensation of two orthophosphate molecules to form one
pyrophosphate molecule: 2K2HP04(solid) -> K4P207(solid) + H20(gas)
(4) The cooled solid product is dissolved in a limited amount of water to obtain the
desired concentrated solution.
Patent US3356123 Apparatus and method for concentrating phosphoric acid
Patent US3371992 Formation of crystalline pyrophosphoric acid
Patent US3408158 Process for separating selected polyphosphoric acids from condensed phosphoric
acid and novel complexes resulting therefrom
Patent US3420627 CONCENTRATION OF PHOSPHORIC ACID
Patent US3440010 METHOD AND APPARATUS FOR MAKING SUPERPHOSPHORIC ACID
Patent US3442611 PROCESS FOR THE PRODUCTION OF HIGHLY CONCENTRATED PHOSPHORIC ACID
viscosity graph fig. 2
Patent US3453074 NOVEL PHOSPHOROUS COMPOSITIONS AND PROCESS
Patent US3457036 VACUUM CONCENTRATION OF PHOSPHORIC ACID
Patent US3526482 APPARATUS FOR PRODUCING POLYPHOSPHORIC ACID
column 1 lines 29+
By polyphosphoric acid, there are understood phosphoric acids having an H3PO4 content of more than 100% H3P04 (72.5% P205) which are produced by adjusting the corresponding ratio between the phosphorus pentoxide and water in suitable manner. In the system P205-H20, two regions free of crystallization exist above 72.5% P205, namely, between 76.0 and 77.5% P205 (105% and 107% H3PO4) and above 81.0% P205 (112% H3PO4)' In order to obtain liquid polyphosphoric acids which are stable against subcooling, the phosphorus pentoxide content is limited to these ranges. The intermediate range of polyphosphoric acids crystallizes upon cooling. The P205 content of the polyphosphoric acids can reach metaphosphoric acid with 89% P205 and even
be higher than this. Methods are already known for producing polyphosphoric
acids having phosphorus pentoxide contents of up to 87% P205 by burning white
phosphorus with air or oxygen containing gases, and absorbing the phosphorus
pentoxide from the combustion gases in phosphoric acid which cover the wall of
the combustion chamber, and at the same time take up the heat of combustion of
the phosphorus.
Patent US3777008 SOLID POLYPHOSPHORIC ACID
------------------------
Making anhydrides of carboxylic acids.
Patent US2061615 manufacture of aliphatic acids, anhydrides, and ketones Again,
in my U.,S. application S. No. 609,251 filed 4th May, 1932, I
have described how acetic anhydride can be produced by similarly treating
acetates of'highly or relatively highly basic, metals in admixture with normal
salts of 35 strong mineral acids.
Patent US2073685 acetic anhydride from metal acetates
Patent US2073686 acetic anhydride from metal acetates
Patent US1693331 acetone + CO2 -> acetic anhydride
Patent US1961542 acetone + acetic acid -> acetic anhydride
Patent US1153402 acetate + nitric anhydride -> acetic anhydride
Patent US0683464 Cl2 and SO2
Patent US1018733 S and Cl2
Patent US1195205 S and Cl2
Patent US1195227 NaHSO3, etc. and acetate
Patent US1283115 -> FR478951 pyrosulfate and acetate
Patent US1926087 metaphosphate and CH3COOH
Patent US1430304 pyrosulfate and acetate
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Phosphoric acid
Patent US3645682 A PROCESS FOR PRODUCING PHOSPHORIC ACID BY THE USE OF ION EXCHANGE RESINS
Patent US4390509 Process for manufacturing ammonium phosphate utilizing an oxalic acid acidulating process
oxalic acid + phosphate --> phosphoric acid
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Shadik
Старый Юный Химик
Oct 9 2006, 20:56
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Neo, thank you. Yoa is the great patent searcher. Thank you.
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Neo Retro
Старый Юный Химик
Aug 25 2007, 19:41
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This article has a Fries rearrangement process using hydroquinone dipropionate on the second and third pages. If you Google "hydroquinone dipropionate" you can find companies that sell it. Its used in cosmetics as a skin lightener. It also suppresses the growth of melanoma cells, at least in mice.
Z. He, F. .J. Davis, G. R. Mitchell
Influence of side-chain bearing units on the phase behaviour of a series of copoly(ester ether)s
Eur. Polym. J., 1996, 32(6), 735-746.
DOI: 10.1016/0014-3057(95)00183-2Присоединённые файлы
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Neo Retro
Старый Юный Химик
Aug 25 2007, 19:46
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A related article from Organic Synthesis.
Submitted by G. C. Amin and N. M. Shah
Checked by R. S. Schreiber and W. W. Prichard
2,5-DIHYDROXYACETOPHENONE
[Acetophenone, 2,5-dihydroxy-; quinacetophenone]
Organic Syntheses, Coll. Vol. 3, p. 280 (1955); Vol. 28, p.42 (1948).
DOI: 10.15227/orgsyn.028.0042
http://www.orgsyn.org/demo.aspx?prep=CV3P0280Присоединённые файлы
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Neo Retro
Старый Юный Химик
Aug 25 2007, 23:40
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More references.
Patent US2413493 Synthesis of isomer-free benzyl methyl acetoacetic methyl ester
Patent US2838570 Process of producing pure halogeno methyl (p-hydroxy phenyl) ketones
separation from phenols using halogenated hydrocarbon solvent
Patent US2848345 Paraffin wax stabilized with a 2, 4, 5, trihydroxyphenyl ketone
Patent US2822378 Method for preparing esters
polyphosphoric acid, phenol esters
Patent US2833825 Preparation of acylphenols
clay catalyst
Patent US3875247 Process for preparing alkylphenols by oxidising alkylbenzaldehydes
Patent US4478754 Preparation of phenyl esters in the presence of boric anhydride
Patent US5808130 Esterification of phenols
Dean Stark trap with toluene
Two articles from Journal of Chemical Education.
Edit: 0 Bytes file size (upload error)
Это сообщение отредактировал namgramk - Aug 15 2013, 20:47
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Neo Retro
Старый Юный Химик
Jun 11 2015, 00:19
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Those two articles from Journal of Chemical Education are the following:
Phenyl acetate preparation from phenol and acetic acid: Reassessment of a common textbook misconception
M. B. Hocking
J. Chem. Educ., 1980, 57 (7), p 527
DOI: 10.1021/ed057p527
The direct esterification of phenols
Robert D. Offenhauer
J. Chem. Educ., 1964, 41 (1), p 39
DOI: 10.1021/ed041p39
Also see
The identification of esters of phenols
Gabriel Carbone
J. Chem. Educ., 1953, 30 (6), p 315
DOI: 10.1021/ed030p315
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