[CH:1]([NH:3][NH:4][C:5](=O)[C:6]1[CH:11]=[CH:10][CH:9]=[N:8][CH:7]=1)=O.P12(SP3(SP(SP(S3)(S1)=S)(=S)S2)=S)=[S:14]>N1C=CC=CC=1>[N:8]1[CH:9]=[CH:10][CH:11]=[C:6]([C:5]2[S:14][CH:1]=[N:3][N:4]=2)[CH:7]=1To a solution of 22 g of N'-formylnicotinic acid hydrazide in 150 ml of pyridine are added, in portions, 28 g of phosphorus pentasulfide. During this addition the temperature rises to 65° C. After 5 minutes the mixture is heated to 110° C. and stirred for 2 hours at this temperature. The pyridine is then distilled off in a water jet vacuum. The residue is taken up in chloroform and the solution is extracted with a 5% sodium hydroxide solution and water. The organic phase is dried and the solvent is removed by evaporation, affording 2-(3-pyridyl)-1,3,4-thiadiazole as a pale yellow powder with a melting point of 78°-79° C.
Wird geladen…