[GinaTageldin]

Hello everybody
1st Q is i was tried to hydrolyse cyano group on pyrazole into amide since this reaction is reported to be prepared by dissolving cyano compound in sulfuric acid stirring over night then crushed ice is added to give a solution which ppt after neutralization by c.NH4OH and allawing this mixture to reach 70 Cecilius upon neutralization , in my experiment everything was good except the step of neutralization not give the product and the total volume of the solution was huge which may hinder the product ppt

2nd Q oxidation of methyl group of pyrazolo pyrimidine ring to aldehyde using selenium dioxide and aq or dry dioxane but TLC was highly impure and no main spot found why?
if i need to do this reaction on a domestic microwave what is your advice to use the appropriate solvent or no solvent condition and time required and how to separate the product
plz i need references 
thanks alot

[Dan]

The only way to diagnose the problem is to find out what happened.

In the first case, you could try an organic extraction and analyse what you get.

In the second case, isolate the products of the reaction and identify them. It's a pain, but really there is no other way to understand why the reaction failed.

[discodermolide]

Conc ammonia may not be strong enough to neutralise all the sulfuric acid, thus you end up with very large volumes. It may be better to use conc. NaOH (30%).

[GinaTageldin]

thank you sir Dan and sir discodermolide for your advice i did the hydrolysis with 2 M NaOH and it works and still the reaction using sulfuric acid neutralization is difficult specially after left the mixture on fridge ppt upon washing with water dissolve and excess ammonia dissolve the product as it is reported that is crystallized from water


for the second reaction please help me if i could do this oxidation step successfully and the precautions that may i missed during reaction or use other reagent than selenium dioxide different solvents use microwave or not

thanks again

[discodermolide]

Just a not in case you do this on a larger scale, conc. sulfuric/ice is a freezing mixture so be careful that the RM doesn't solidify.

For the oxidation perhaps a higher boiling solvent may help, microwave heating as well.
However with all the nitrogens the oxidation may well be messy. As Dan said you may have to isolate the various products to see what is going on.
Have you done a lit. search on this oxidation?

[orgopete]

... i did the hydrolysis with 2 M NaOH and it works....

This is what one would predict. Acidic hydrolyses of nitriles are difficult as the amide intermediate is more basic than the nitrile. Therefore the hydrolyses will tend to go to the carboxylic acid. Under basic conditions, addition to the nitrile is relatively facile, but hydrolysis of an amide requires vigorous conditions. An amide must form a dianion intermediate in order to expell NH2(-) anion. Therefore basic hydrolysis of a nitrile to a carboxylic acid is more difficult.