The compounds indicated by you are obtained by deamination of 3,5-dialkyl-4-amino-1,2,4-triazoles (by the action of hydrochloric and nitrous acids). Starting materials can be obtained by reaction of carbo[ylic acids with hydrazine hydrate. Or indicated by youcompounds are obtained by cyclization of acylaminohydrazones of carboxylic acids. The starting materials are obtained from iminoesters and hydrazides of carbonic acids. If you need more detailed methods, tomorrow, I'll look for them specifically.
RC(NH)OMe + R1C(O)NHNH2 = R1(CO)NH-N=C(NH2)R
cyclisation "minus water" (heating 80-100 0C) You Have Your triazole
Thank you very much for your valuable suggestions Dr. Perkins. If you have any reference, please share with me. Bcz I need to prepare sensitive derivatives of this triazole.
The sypmles and more common methodolody I know, is russian "Zhurnal Obscheij Khimii" (Journal of General Chemistry) 1959 p2141. May be You can not find this yournal so I shell desribe You the methodology. It is very simple.
1) Iminoester RC(NH)OMe (free base). Or if it is hydroclodide made freshly from nitrile and gaseous HCl, You have to add one equvanent of NaOH. Dissolve in dry ethanole and add hydrazone (R1C(O)NHNH2). Reflux for 2-3h, solvent distill off add water and crystallise from EtOH
2)The second step could be done in a "neat" method. Obtained acylaminohydrazones gradually heat to melting point and then 10-15 0C higher untill all water will ditill off. After cooling cristallise obtained solid from alcohole. If this method too dengerous fol "living" of your compound You may use boiling in toluene or any other solvent to distill off water. The yields are up to 90%.
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