Perhaps microwaves is the solution

first of all u make a k salt of SH group by K2CO3 then react with hydrazine, probably its

give better result.

Abdelazeem,

I understood that you have thiol on C=N [N=C-S-H] and you would like to transform it to N=C-NH-NH2 or N=C-NH-NHR. If I am right then the reaction is like nucleophilic acyl substitution where the NH2---X is a nucleophile and SH is the leaving group. So, how do you do it

1- transfer S-H to S-Me then try the reaction if you want to

or

2- transfer S-Me to S(O)Me then try it

or

3-transfer S(O)Me to S(O)2Me then try it [it should work S(O)2Me is a good leaving group] ............This is a known procedure for such transformation.

Please, see

--- Barlin, Gordon B. and Brown, William Vance, Oxidation, reduction, and replacement reactions of the methyl-sulfinyl group in substituted six-membered nitrogen heterocycles, Journal of the Chemical Society [Section] C: Organic, (6), 921-3; 1969.

---Thede, Kai et al., Substituted dihydropyrazolones for treating cardiovascular and haematological diseases, PCT Int. Appl., 2008067871, 12 Jun 2008.

--- Peseke, K. and Schoenhusen, U., Push-pull butadienes. XI. Syntheses and reactions of (methylsulfonyl)nicotinonitriles, Journal fuer Praktische Chemie (Leipzig), 332(5), 679-86; 1990.

I should note that this type of reaction [Nucleophilic Acyl Substitution Reaction] could indeed be accelerated by microwave irrad. as Kaufmann mentioned earlier. see

---Synthesis of 3-Benzyl-2-substituted quinoxalines as a Novel Monoamine Oxidase A Inhibitors, S. Yaseen, S. Kattab, Adnan Bekhit,and Adel Amer Bioorg. Med. Chem. Lett. 16, 1753-1756 (2006).

Good luck

I agree with Dr. Adel says and specifically last statement: Synthesis of 3-Benzyl-2-substituted quinoxalines as a Novel Monoamine.

For such reaction, I use

1. reaction of excess hydrazine hydrate

2. mixture 1-butanol - hydrazine hydrate

I agree with Adel Amer, especially with the methylation part. I vote for the methylation and then the microwave with the excess of the hydrazine. Thiol is not the best leaving group, whereas the SMe group works fine e.g. on pyrimidines. If this fails, you can still oxidize.

Drive the reaction forward by addition of a thiophillic Lewis acid. AgOAc should be compatible to your system.

The best way to transform thiol to respective hydrazine is to do methylation first and thereafter reaction with hydrazine (1.5mole) in ethanon under reflux condition.No doubt one can convert thiol to hydrazine but it requires harsh condition and complete conversion takes time.

i myself also agree with Adel Amer. i am myself doing this type of reaction using methyl iodide in DMF/TEA for methylation and then oxidising with m-CPBA in DCM or choroform at room temp.for few hours to form SO2CH3 as leaving group and then replacing it with hydrazine in THF , etc at rt.

I like Adel Amer's solution. Depending on the heterocycle but SMe group or the sulfoxide or sulfone are good leaving groups.

Yoy can heat thiol with hydrazinedirectly & keep it for some days to get hydrazide