Nermin Salah

6 Questions 6 Answers 0 Followers

Questions related from Nermin Salah

What are the best reaction condition for amide coupling using HBTU?

Tips and tricks for amide coupling of benzidine with Formylbenzoic acid, I plan to use HBTU, any advice how to maximize yield and minimize byproducts?

25 November 2024 1,310 4 View

Can I selectively esterify phenolic OH without affecting NH2 in the molecule?

A benzophenone bearing an OH at position 4 of one ring and ethylamine at position 4' at the other ring; can I esterify OH without affecting NH2 ; Protecting NH2 will not solve problem as during...

11 February 2018 4,936 1 View

How can I increase the ionization of organic molecules so I can analyze them using ESI MS/MS, I tried +/- ionization mode?

I have some organic molecules (carbamate derivatives) they show UV absorption yet looking in the mass scan , I can not see any ionization , I have tried positive and negative mode of ionization...

19 October 2016 1,133 3 View

What are best chromotographic conditions for carbamate derivative analysis via LC/MS?

I have been trying to determine some carbamtae derivatives using LC/MS, I am using ESI/positive ion mode ; gradient elution: water+0.1 % TFA then acetonitrile+ 0.1 % TFA but no ionization is...

10 February 2016 3,731 4 View

Any advice about the stability of ester and carbamate containing compounds?

How can I prevent compounds with ester and carbamate group on a phenyl ring from hydrolysis even though I keep them in freezer with no solvent still I face excessive hydrolysis that is obvious in...

25 November 2015 506 3 View

N-BromoSuccinimide (NBS) reaction

I am using N-BromoSuccinimide (NBS) to brominate an allylic carbon, I am using CCl4, benzoyl peroxide and light. The starting material disappeared yet no brominated product was obtained, LCMS...

01 January 1970 906 3 View