14 votes

What is the best way to deprotonate a methyl group?

The deprotonation of 1a has been conducted with LDA/THF and subsequently converted to the phosphonate.[1] Alternatively, bromide 3a has been prepared[2] and converted[3] to phosphonate 2a via an ...
user55119's user avatar
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9 votes

Question about the differences of white and grey NaH properties

Sodium hydride on mineral oil is grey. When it reacts with water, for example from air humidity it reacts to NaOH which leads to discolouration which is white. One can wash NaH with hexane or THF to ...
raptorlane's user avatar
7 votes
Accepted

Why will changing the solvent crack the column for column chromatography?

The fundamental reason for cracks in packed beds is that all chromatography columns (used in organic labs or even HPLC) do not have particles packed in a regular crystalline manner. This means that ...
AChem's user avatar
  • 39.8k
5 votes

Question about the differences of white and grey NaH properties

Washing in dry pentane was my first thought, too (already visible from the freely available abstract of eEROS). Regarding the determination of the concentration of the active reagent: in the chapter ...
Buttonwood's user avatar
5 votes

Why will changing the solvent crack the column for column chromatography?

The model of liquid chromatography with a stationary phase (silica, alumina, ...) and a mobile phase (your eluent / eluent mixture) is a simplification. If your liquid chromatography is not based on ...
Buttonwood's user avatar
4 votes
Accepted

Selective formation of enolates

A few comments are in order as to the way in which the enolate formation is conducted. Lithium diisopropylamide (LDA) is formed in situ from the free amine and n-BuLi at -78oC at which temperature the ...
user55119's user avatar
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4 votes
Accepted

Can any compound form into an amorphous solid?

Whether a substance crystallizes or not largely depends on the rate of cooling or loss of solvent. K. Gibson states, "Cooling materials super-quickly... prevents the normal crystalline ...
DrMoishe Pippik's user avatar
4 votes

Are these reactions in synthesis of melamine correct?

In the first step, urea decomposes into cyanic acid and ammonia: $$\ce{(NH2)2CO -> HNCO + NH3}$$ Cyanic acid polymerizes to cyanuric acid, $$\ce{3 HCNO -> (HO)3C3N3}$$ which condenses with the ...
Poutnik's user avatar
  • 40.8k
4 votes

Why will changing the solvent crack the column for column chromatography?

Silica gel is polar. Hexane is non-polar. DCM (dichloromethane) is polar. Adding polar solvent to the column too quickly could cause uneven permeation into the column packing. But the main concern ...
Robert DiGiovanni's user avatar
3 votes

Finding chromium

In some river systems chromite is a relatively common mineral. One could extract it in a similar manner to gold: panning, sluicing, etc. In certain rivers and creeks draining the right geology one ...
Tom P's user avatar
  • 391
2 votes

Partial reduction of anthraquinone to anthrone using stannous chloride?

Luca: Your mechanism looks good except you haven't resolved the reductive elimination in the last step. Assuming that the carbonyl oxygen is protonated as in 1a, then two events must occur in some ...
user55119's user avatar
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2 votes

Nickel(II) acetylacetonate crystals coming out blue

You obtained the dihydrate complex of AAN. If you want to obtain green crystals, you should use azeotropic evaporation to remove crystal water. Then you will have green product - anhydrous AAN.
Сергей Егоров's user avatar
2 votes

Have IH₃ and IH₅ already been synthesized?

Not the specific compounds $\ce{IH3}$ and $\ce{IH5}$, but hydrogen-iodine compounds with nonclassical stoichiometriws have been synthesized under high pressure. Binns et al[1] report two high-pressure,...
Oscar Lanzi's user avatar
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2 votes

Synthesis of anthranilic acid

You have to do the first part of the reaction in an ice bath with vigorous stirring. You added the acids backwards. Start with conc. HCl to about pH 8 then add glacial acetic acid (AA) drop wise. The ...
user135132's user avatar
2 votes

How to prepare iron(II) carbonate from iron(III) chloride?

This is the simplest method I can think of: $\mathrm{2FeCl_3+Fe\rightarrow3FeCl_2}$ $\mathrm{FeCl_2+Na_2CO_3\rightarrow FeCO_3+2NaCl}$ It only uses iron metal and sodium carbonate, which are readily ...
Sticklink's user avatar
2 votes
Accepted

Production SnO2 nanoparticles through chemical co-precipitation method: chemical equation of the reaction

Tin(II) chloride $\ce{SnCl2}$ is not perfectly soluble in pure water. It is only soluble in aqueous $\ce{HCl}$ solutions. In pure water $\ce{SnCl2}$ is partially hydrolyzed according to the ...
Maurice's user avatar
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2 votes

How do I synthesize salicylic acid?

Riemer and Tiemann originally reported that using carbon tetrachloride in place of chloroform gives salicylic acid as major product plus p-hydroxybenzoic acid. It is mentioned in this review by ...
Waylander's user avatar
  • 21.9k
2 votes

Reaction of eugenol with concentrated hydrobromic acid in the presence of gaseous hydrogen bromide

Consulting the oracle of wisdom that is Greene's "Protective Groups in Organic Synthesis" produces this reference that describes the cleavage of dialkyl and aryl alkyl ethers with 47% aq HBr ...
Waylander's user avatar
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2 votes

Are these reactions in synthesis of melamine correct?

So are there two methods of obtaining melamine; one by decomposing 6 moles of urea and another by mixing 6 moles of cyanic acid with 3 moles of ammonia? That's not what the article is saying. The ...
John Bollinger's user avatar
2 votes

Should I remove inhibitor from methyl acrylate?

It is common for the hydroquinone inhibitor to be added to aclates to prevent polymerization during storage. It is possible that MEHQ could react with the amine and hinder the aza-Michael addition. To ...
Alex's user avatar
  • 93
1 vote

Should I remove inhibitor from methyl acrylate?

I would not worry that the typical polymerization inhibitors added to acrylic esters will interfere with the aza-Michael reaction. I guess you will add the amine in excess, and the relatively small ...
Snijderfrey's user avatar
1 vote

Synthesizing "Methyl 2-(2-oxopyrrolidin-1-yl)-2-phenylacetate"

I would start from the commercially available Methyl alpha-chlorophenylacetate (CAS 7476-66-6), react this with pyrrolidine and then oxidise the product with RuCl3/NaIO4 as reported Sharma & ...
Waylander's user avatar
  • 21.9k
1 vote
Accepted

Magnesium chloride to citrate conversion (reaction/synthesis)

Eventual direct mixing of $\ce{MgCl2}$ and $\ce{H3Citr}$ to get $\ce{MgH-Citr}$ and $\ce{HCl}$ and eventual precipitation of the citrate would hit the stumble stone of acidification of solution, ...
Poutnik's user avatar
  • 40.8k

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