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Author Topic: Short Question Thread 2.0  (Read 5709 times)

fishinabottle

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Re: Short Question Thread 2.0
« Reply #320 on: March 03, 2013, 03:33:15 PM »
One moment, the writeup you are following says there was a colorchange to light yellow. You got a colorchange to light yellow (looks fine btw).
The next step in the writeup is getting 100something yield (whats against the laws of thermodynamic but well...).
Why dont you dance on the table in expectation of the yields which hopefully are to come over you?

Different methodic gives different reactions, apples and mangos comparing you understand?

Chromic did not tell bullshit.
Go on!

/ORG

Tsathoggua

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Re: Short Question Thread 2.0
« Reply #321 on: March 03, 2013, 06:56:23 PM »
Read just the other day of a method for dehydrating some transition metal chloride salts, in the context for preparing the anhydrous salts for use as lewis acids (in this case for the synthesis of alkyl halides) that simply refluxes the salt in question in thionyl chloride.

Toady assumes that SO2Cl2, S2Cl2 and SCl2 would react likewise, being prone to hydrolysis back to SO2, HCl in the first case, and to HCl in the latter two. He has handled thionyl chloride before, but not the other halides. For those with experience with those three, particularly S2Cl2 and SCl2, which is the most susceptible to hydrolysis (and thus best suited to push the equilibrium between salt hydrate and anhydrous salt towards the right?)

And how stable towards weak base are these? is it practical to use carbonates/bicarbonates to trap the acidic hydrolysis products? Toady is all for recycling where possible. Always more appealing when one can make use of the leftovers, rather than simply venting or having them end up in the local sewer works :)

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EMTWC

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Re: Short Question Thread 2.0
« Reply #322 on: March 12, 2013, 12:54:40 AM »
two n00b short questions, if I may:

1) are MeNO2 and CH3NO2 the same things, or more specifically, can  CH3NO2 be used in a nitromethane/Hg amalgam?

2) can heet be used as a MeOH source straight, or does it require dirtillation to remove that 1% proprietary additive?

comparing brightstar vs. methyl man, and attempting the bromosafrole route over the next few...

thx
roll some bones and catch a fire

Whale

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Re: Short Question Thread 2.0
« Reply #323 on: March 12, 2013, 01:11:15 AM »
Quote from: EMTWC on March 12, 2013, 12:54:40 AM
1) are MeNO2 and CH3NO2 the same things, or more specifically, can  CH3NO2 be used in a nitromethane/Hg amalgam?
MeNO2 is nitromethane, and so is CH3NO2, so yes it can be used.

Quote from: EMTWC on March 12, 2013, 12:54:40 AM
2) can heet be used as a MeOH source straight, or does it require dirtillation to remove that 1% proprietary additive?
it can usually be used as-is, but if you want to get off that extra 1% of water (like in jon's route) use a drying agent, or my favorite; lithium from batteries

EMTWC

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Re: Short Question Thread 2.0
« Reply #324 on: March 12, 2013, 02:34:56 PM »
Quote from: %1 on March 12, 2013, 01:11:15 AM
Quote from: EMTWC on March 12, 2013, 12:54:40 AM

it can usually be used as-is, but if you want to get off that extra 1% of water (like in jon's route) use a drying agent, or my favorite; lithium from batteries

less concerned about any water, at least this time round. the iso-heet (isopro alc) has a yellow tint which would indicate their proprietary additive is more than water. Have not opened the heet to see if its the same color.
most of the synths call for MeNO2 as apposed to CH3NO2. I could only find the two were nitromethane, nothing on the different formulas so felt it wise to ask.
roll some bones and catch a fire

Sydenhams chorea

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Re: Short Question Thread 2.0
« Reply #325 on: March 13, 2013, 06:41:40 AM »
Dealkylation of ethylvanillin (3-ethoxy-4-hydroxybenzaldehyde; bourbonal) with H2SO4 is said to be a better option yield-wise then plain vanillin.

Does anyone know the reference where ethylvanillin is dealkylated with conc. sulfuric acid?
It is perhaps the narcotic. Hyoscine affects certain people very oddly. One cannot be sure. Sometimes, these cases take strange forms. The victim becomes in a sense, 'mediumistic', a vehicle for all the intangible forces in operation around her.

Polonium

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Re: Short Question Thread 2.0
« Reply #326 on: March 20, 2013, 01:41:50 AM »
Quote
De-ethylation of 3-ethoxy-4-methoxybenzaldehyde

After having established an atmosphere of inert gas, 270.5 g of 3-ethoxy-4-methoxybenzaldehdye and 742 g of 98% sulphuric acid are loaded into a 1.5 liter jacketed reactor equiped with a mechanical stirrer, a thermometer and a nitrogen input.

The mixture is heated for 3 hours 30 mins at 65OC. The assay by high performance liquid chromatography gives:
    Conversion of the EMBA = 98.5 %
    Yield of isovanillin = 96 %

The reaction mass in cooled and run into 2 litres of ice-cold water, with stirring. The precipitate which forms is dissolved with 2 liters of methyl isobutyl ketone. The organic phase is separated out; the aqueous phase is re-extracted with 0.75 liter of methyl isobutyl ketone. The mother liquors (30% H2SO4) may be regenerated. The organic phase is washed to pH = 7 and is then evaporated at 60 C under a reduced pressure of about 100 mm of mercury (13300 Pa), to give isovanillin (214 g) in a purity equal to 95%

The dealkylation above is from a 1997 US patent:

Process for the preparation of isovanillin
Maliverney, Christian (Lyons, FR); 1997 Rhone-poulenc, Chimie (Courbevoie, FR)   
United States - Patent No: 5648552 - http://www.freepatentsonline.com/5648552.html

As far as I can see there should be no problem applying the same scheme to ethyl vanillin. The authors in this patent methylate the p-phenol first to ensure selectivity for isovanillin but it appears this dealkylation process works for any alkyl group 2 or more carbons in length.

Intimissimi

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Re: Short Question Thread 2.0
« Reply #327 on: March 24, 2013, 10:07:04 PM »
Ergotamine (30 g, 0.0515 mol) was hydrolyzed using 2 h re?ux with KOH (4 g) in 120 ml of water:ethanol (1:3). The resulting mixture contained lysergamide (39.1 mol.%), isolysergamide (35.9 mol.%), lysergic acid (8.9 mol.%) and isolysergic acid (3.0 mol.%).

How much grams of lysergamide-LSA and lysergic acid was obtained?

Nothing I get makes sense.

newbiechem

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Re: Short Question Thread 2.0
« Reply #328 on: March 25, 2013, 02:40:03 AM »
WOW 30gr ergotamine!!!!!!! you made yourself?
im missing something? hehehehe 

fractal

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Re: Short Question Thread 2.0
« Reply #329 on: March 25, 2013, 09:42:18 AM »
Quote from: Intimissimi on March 24, 2013, 10:07:04 PM
Ergotamine (30 g, 0.0515 mol) was hydrolyzed using 2 h re?ux with KOH (4 g) in 120 ml of water:ethanol (1:3). The resulting mixture contained lysergamide (39.1 mol.%), isolysergamide (35.9 mol.%), lysergic acid (8.9 mol.%) and isolysergic acid (3.0 mol.%).

How many grams of lysergamide-LSA and lysergic acid was obtained?

Nothing I get makes sense.

Ex.
Lysergic Acid
.0515mol x .089 = .0045835mol of lysergic acid

.0045835mol x 268.31g = 1.23g lysergic acid

Just do the same thing for the rest. Convert the % yield to a decimal by multiplying it by .01, multiply this by the number of moles of the reactant, and then multiply that by the molar mass of the product. You should check out a general chemistry text, this type of thing is usually covered in the first 2-3 chapters.

lugh

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Re: Short Question Thread 2.0
« Reply #330 on: March 25, 2013, 07:33:48 PM »
Does anyone know the reference where ethylvanillin is dealkylated with conc. sulfuric acid?

The article that foxy2 originally posted on the Hive that was uploaded by another member long ago in:

https://the-collective.ws/forum/index.php?topic=291.msg3975#msg3975

has been reuploaded in the same thread:

https://the-collective.ws/forum/index.php?topic=291.msg165686#msg165686

may be what's desired  ;)  The end results from the effort applied  8)
Chemistry is our Covalent Bond

blobla

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Re: Short Question Thread 2.0
« Reply #331 on: March 26, 2013, 03:33:46 AM »
Let's say I chlorinate some toluene to mostly  benzal chloride (and some  benzotrichloride) - can I then hydrolize that mix directly to benzaldehyde/benzoic acid? Or  do I have to distill/purify  the benzal chloride before the hydrolisis?

blobla

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Re: Short Question Thread 2.0
« Reply #332 on: March 26, 2013, 03:35:42 AM »
By the way, why does the forum software think the year is 2012?

Whale

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Re: Short Question Thread 2.0
« Reply #333 on: March 26, 2013, 04:07:32 AM »
I think its manually updated and they just havent fixed it yet

ImAMANGUYS

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Re: Short Question Thread 2.0
« Reply #334 on: March 27, 2013, 03:47:21 AM »
Methanol, water, isopropyl alcohol, ethanol, ect... Look it up brah! I dont believe acetone alone is perfered for recrystallization. Utfse.

newbiechem

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Re: Short Question Thread 2.0
« Reply #335 on: March 27, 2013, 04:03:11 AM »
i know all these will recrystilize it, but that wont take the yellow color-impurities out like the acetone wash....
maybe im saying it wrong.... i dont want big crystals,or anythinkg like that, i want to clean, take the yellow impurity out...

what i said is that if i do a simple recrystalization, the color (impurity) will remain....or im wrong? thats what i think if i just dissolve and recrystilize it....
or maybe im wrong and i would love to know it if i am..... so if i simple recrystalize most of the yellow impurities will go away? if so, hows that? i mean where does it go? or become more goey yellow that wont dry? with acetone wash, i know the mda wont dissolve and most impurities will, so yellow goes away on the acetone....thats what i want....but if you telling me recrystalize will do it... i said acetone because most ways ive seen (yes i used tfse) used acetone, most like 2 solvents recristalization.

but thank

ImAMANGUYS

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Re: Short Question Thread 2.0
« Reply #336 on: March 27, 2013, 07:07:04 AM »
The whole point of recrystallization is to recrystalyze the salt without the impurities crystalizing along with the desired crystal lattice. A wash is what you're doing with the acetone. In this way, with cold acetone, the mda or mdma is mostly insoluable, which removes most of the junk. Recrystallization however reforms the crystals removing the "trapped" impurities. These dissolve into the solvent of choice. If slow cooling is performed then most of the impurities remain outside the crystal lattice (crystals or salts as you see them) and remain inside the solvent. At this point you would filter. Have you read vogels organic chemistry survival guide? Its a must read for newer chemists ;) both would be good, but using only a wash or one recrystallization may suffice. but that manual will be your bible i swear!

 Just a suggestion! Goodluck.

ImA
« Last Edit: March 27, 2013, 07:09:50 AM by ImAMANGUYS »

4studiesonly

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Re: Short Question Thread 2.0
« Reply #337 on: March 29, 2013, 02:47:23 PM »
When wanting to separate an aldehyde(C7H6O or C8H6O3) from oil or alcohol using and forming the bisulfite adduct.
Instead of using Sodium bisulfite or rather Sodium metabisulfite which is cheaper could one use Potassium metabisulfite(more or less free)?
Bis zum bitteren ende

vict

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Re: Short Question Thread 2.0
« Reply #338 on: March 29, 2013, 03:23:44 PM »
There may be some solubility differences when making a saturated solution of potassium vs. sodium metabisulfite, but yes, either would work.

Electro´S

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Re: Short Question Thread 2.0
« Reply #339 on: March 29, 2013, 09:13:27 PM »
Hi, has someone any idea about this crazy workup?
From where is the wire and where is the wire going ?
I can imagine a soxhlet with the NaBH4 inside, but ...
Can any one help me?

____________________________________________it was recently discovered that adding NaBH4 to a refluxing mixture of EtOH and nitrostyrene substrate through a soxhlet capsule attached to the lower end of a reflux condensor by means of chemically inert wire provided a method of unattended reduction, using very low molar equivalents of NaBH4 (0.8-1.2), which is apparently due to the use of refluxing solvent which raises solubility and reactivity.

oh it's very very easy to imagine.

take a reflux condenser.
take a soxhlet paper capsule.
take wire and attach the capsule to the wire so you have a U shaped wire, the wire goes at the top of the capsule.
take the 2 open ends of the wire and bend one to form a hook which you can attach to the inner spiral of the reflux condenser so your solvent drips right into the soxhlet capsule.

thats it!
___________________________________
hxxp://www.sciencemadness.org/talk/viewthread.php?tid=5436
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