New answers tagged

3

Here is a possible route: Start from the commercially available 2,6-dichloro-5-fluoropyridine-3-carboxylic acid (1). Form the Weinreb amide (2) via the acid chloride. React this with vinyl magnesium bromide to form (3). React the product with 1 eq of aniline in the presence of non-nucleophilic base to produce (4). Isolate this product and react with excess ...


0

All the reaction doesn't occur just in one pot. First, BuLi removes the tributylstannyl substituent from the compound 1 in nearly 0.5 h. Then, by adding the amide 3 the reaction pot, the anion 2 attacks to the carbonyl group only once to provide the ketone 4 without any tertiary alcohol, as expected by the Weinreb–Nahm reaction. Isono, .N., & Mori, .M. (...


5

The description you provided is essentially a shorthand for a standard workup procedure. After performing a reaction, one wants to isolate one’s product while removing the catalyst or other reagents and side products that one doesn’t need. For example, in many cross-coupling reactions an inorganic halide salt is an undesired side-product and a base such as ...


10

The solvent of this experiment should be non polar, and may be a hydrocarbon, or a chlorinated hydrocarbon. This organic phase may contain as impurities some acids and other polar substances soluble in water, that should be eliminated. This liquid is then mixed with an aqueous solution of soda $\ce{NaHCO3}$. Aqueous solutions and non polar substances are not ...


19

This is standard for purifying substances. To wash means to add your product solution to an aqueous solution (or just water, but frequently a saturated solution) to a separatory funnel. After shaking, you drain the lower layer (which is usually aqueous). This process removes water soluble impurities. This is frequently repeated. Drying is accomplished by ...


2

By "gaseous titanium", do you mean "titanium tetraiodide ($\ce{TiI4}$) vapor"? Van-Arkel De-Boer process is a purification process of titanium and zirconium. Basically, what happens is that the impure metal, let's say titanium is heated in iodine environment at a temperature of $\ce{250 ^\circ C}$ to form volatile titanium tetraiodide ($\...


6

Divide your alkene starting material in two portions - one twice the amount of the other. Take the larger portion and do an anti-Markovnikov addition of HBr to it using peroxide or light reference to give the terminal bromide (1-Bromo-4,4-dimethylpentane). Take the smaller portion and ozonolyse it, working up with Dimethyl Sulfide to give the aldehyde (3,3-...


0

The phosphate ion is of vital importance in biological systems. Its molecular geometry is tetrahedral. Thus, based on the $\mathrm{pH}$ of the system, hydroxy groups are inter-changeable with $\ce{P=O}$ form and hence all three remaining $\ce{O}$s are equivalent (see Waylander's comment). Therefore no impact on the dehydration. However, the stereochemistry ...


3

$\ce{NH3}$ and $\ce{SCl2}$ form $\ce{NH4Cl}$ which evolves as white fumes. $\ce{NH4Cl}$, when passed through $\ce{SCl2}$ (cherry-red liquid), gives the appearance of dense-pink fumes $$\ce{\underset{(cherry red)}{6SCl2} + 16 NH3 -> S4N4 +2S + \underset{(white)}{12NH4Cl}}$$ That is why the fumes of $\ce{NH4Cl}$ turned pink


12

The current methods employed for synthesis fall into the following three categories1: Chemical synthesis Biochemical methods Isotope exchange reactions Chemical Synthesis: Most chemical syntheses involving $\ce{^14 C}$ are done with Grignard reagent and $\ce{^14 CO2}$ or $\ce{^14 CN-}$. As an example, Benzene-14 is synthesized as such2: Basic preparatory ...


Top 50 recent answers are included