Electric Literature of 762240-92-6, As we all know, there are many different methods for the synthesis of a compound, and people can choose the synthesis method that suits their own laboratory according to the actual situation. 762240-92-6 name is 3-(Trifluoromethyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyrazine hydrochloride, This compound is widely used in many fields, so it is necessary to find a new synthetic route. The downstream synthesis method of this compound is introduced below.
Example-17:Preparation of (R)-3-azido-l-(3-(trifluoromethyl)-5,6-dihydro-[l,2,4] triazolo[43-a]pyrazin-7(8H)-yl)-4-(2,4,5-trifluorophenyl)butan-l-one.;To 6 gms of (R)-methyl 3-azido-4-(2,4,5-trifluorophenyl)butanoate, added 30 ml of water and 30 ml of tetrahydrofuran. Added 2.0 gms of lithium hydroxide and stirred the reaction mixture for 4 hrs at 25-300C temperature. Acidify the reaction mixture using cone, hydrochloric acid and extracted the compound using ethyl acetate. Distilled off the solvent completely under reduced pressure. To the obtained residue added 24 ml of dimethylformamide and cooled the reaction mixture to 0-50C. 3.5 gms of N,N’- dicyclohexylcarbodiimide (DCC) was dissolved in 10 ml of dimethylformamide and make upto 20 ml. Added 7 ml of above prepared NjN’-dicyclohexylcarbodiimide (DCC) solution to the above 0-50C cooled reaction mixture. Added 3.5 gms of 3- (trifluoromethyl)-5,6,7,8-tetra hydro-[l,2,4]triazolo[4,3-a]pyrazine hydrochloride and 3.3 ml of triethylamine to the reaction mixture and stirred for 15 minutes. Added 0.75 gms of dimethylaminopyridine (DMAP) and stirred the reaction mixture for 3 hrs at 0-50C. Added 6.5 ml of N,N’-dicyclohexylcarbodiimide solution and stirred for 3 hrs. Again added 6.5 ml of N,N’-dicyclohexylcarbodiimide solution and stirred for 3 hrs at 0-50C. Raised the temperature to 25C and stirred the reaction mixture for 12 hrs at same temperature. The unwanted precipitated solids were separated by filtration and to the filtrate added water and ethyl acetate. Separated the both aqueous and organic layers. Washed the organic layer with 5% hydrochloric acid solution followed by washed with 5% sodium bicarbonate solution. Distilled off the solvent completely under reduced pressure. Added 30 ml of isopropyl alcohol to the obtained compound and stirred for 45 minutes at 25-300C temperature. Filtered the precipitated solid and dried the material. To the obtained compound added 10 ml of isopropyl alcohol and 3.8 ml of cone, hydrochloric acid. Stirred the reaction mixture for 3 hrs at 500C. Cooled the reaction mixture to 25C and added water. Extracted the compound from reaction mixture with methylene chloride. Distilled off the solvent completely to get the title compound. Yield: 4.5 gms.
At the same time, in my other blogs, there are other synthetic methods of this type of compound, 3-(Trifluoromethyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyrazine hydrochloride, and friends who are interested can also refer to it.
Reference:
Patent; MSN LABORATORIES LIMITED; SATYANARAYANA REDDY, Manne; ESWARAIAH, Sajja; SATYANARAYANA, Revu; KONDAL REDDY, Bairy; SRINIVAS, Aluru; WO2010/122578; (2010); A2;,
Pyrazine – Wikipedia,
Pyrazine | C4H4N2 – PubChem