79-19-6

99-94-5

26907-54-0

General procedure for the synthesis of 5-p-tolylphenyl-2-amino-1,3,4-thiadiazole from aminothiourea and p-toluic acid: 5.1.1 Synthesis of 5-(4-morpholinophenyl)-1,3,4-thiadiazol-2-amine (59) 4-Morpholino benzoic acid (5.18 g, 25 mmol) and N-amino thiourea (2.28 g, 25 mmol) were dissolved in POCl3 (7 mL) and stirred vigorously at 75°C for 0.5 hr. After the reaction was completed, H2O (30 mL) was added and the reaction mixture was heated to reflux for 4 hours. Subsequently, the reaction solution was adjusted with 50% NaOH solution to pH 8. The mixture was filtered and the resulting filter cake was recrystallized with ethanol to give 3.90 g of yellow crystalline compound 59 in 59% yield. Compounds 60-81 were synthesized in the same way. 5.1.1.4 Synthesis of 5-(p-tolyl)-1,3,4-thiadiazol-2-amine (63) Yield: 98%, Melting point: 194-195 °C (EtOH). eSI-MS m/z: 192.3 [M + H]+; 1H NMR (DMSO-d6) δ 2.34 (s, 3H), 7.27 (d, J = 8.4 Hz, 2H), 7.35 (s, 2H), 7.64 (d, J = 8.4 Hz, 2H).