New answers tagged

0

Positron emission tomography (PET) has been taken using $\ce{^{11}C}$- and $\ce{^{18}F}$-labelled reagents, although they are not $\beta_2$-agonists (Ref.1). The abstract states that: Positron emission tomography (PET) provides three-dimensional images of the distributions of radionuclides that have been inhaled or injected into the lungs. By using ...


2

My thoughts are along the lines of @Andrew and @Waylander. Step F doesn't tell us much, @orthocresol! I prefer a cyclization, 1 $\rightarrow$ 2a, followed by hydrolysis of ester 2a to alcohol 2b. Alternatively, N-O bond homolysis with light would probably involve a cage mechanism. .


-1

EDIT: I miss read the image and saw a carbonyl group where there was an alkene. This explanation has been changed. This is my guess on what is occurring (an electrophilic addition to an alkene): The nitrogen-oxygen bond on the amide is severed, forming a carboxylic acid an an electron deficient amide. The electron pair of this carboxylic acid is stabilized ...


1

You can make the silicates by fusing the hydroxides with silica. Potassium silicate fertilizer grade are successfully produced by direct fusion of silica ($\ce{SiO2}$) and potasium compounds($\ce{KOH}$ and $\ce{K2CO3}$) in furnaces at temperatures up to melting point of mixture. The fusion temperature reaches around 1350 °C. $$\ce{SiO2 + 2 KOH ->[\Delta] ...


5

Hydrolysis of nitrile is pH dependent. It will lead to formation of different products based on pH. Theoretically, nitrile hydrolyze to form amide and then ammonium salt. $$\ce{RCN ->[H2O] RCONH2 ->[H2O] RCOONH4}$$ But in practice, the reaction between nitriles and water is so slow that it is considered negligible. The nitrile is instead heated with ...


2

Yes, you are correct. For converting a nitrile to amide, we do controlled hydrolysis. So, first amide is obtained and then ammonium salt of the carboxylic acid is obtained. So, the reaction would be $$\ce{RCN}+2 \ce{H_2O_2}+\ce{OH^{-1}} \ce{->} \ce{RCONH_2} +\ce{O_2}+\ce{H_2O}$$ Which is done at $\mathrm{pH}$ range of 7-8. If you increase or decrease the $...


0

Phenol is C6H6O, essentially adding one oxygen atom to benzene. The cumene process allows the sharing of two oxygen atoms between benzene and propene and make phenol and acetone. Similarly the similar process by Exxon-Mobil allows the sharing between benzene and cyclohexane which is produced by hydrogenation of benzene. Therefore, I think the readers can see ...


5

By definition, N-nitrosamines are aliphatic or aromatic derivatives of secondary amines, which have a nitroso group ($\ce{–NO}$) attached to nitrogen. In general, N-nitroso compounds are usually formed by the interaction of a nitrosating agent ($\ce{NOX}$) derived from either nitrite salts or nitrogen oxides with an amino substance such as secondary and ...


Top 50 recent answers are included