Thermal method Method A To a mixture of E

Thermal method
Method A
To PD 173074 mixture of (E)-3-(dimethylamino)-2-(phenylsulfonyl)-1-(thiophen-2-yl)prop-2-en-1-one (5) (3.21 g, 10 mmol) and 3-amino-l,2,4-triazole (2) (10 mmol) in pyridine (25 ml) was refluxed for 12 h, then left to cool. The excess pyridine was evaporated in vacuo and the residual solid was taken in ethanol then collected by filtration, washed several times with water, dried and finally recrystallized from DMF/H2O to afford the corresponding triazolo[1,5-a]pyrimidine (10).
Microwave methods (MW)
Method B
A mixture of the enaminosulfone 5 (3.21 g, 10 mmol) and 3-amino-l,2,4-triazole (2) in isopropyl alcohol (10 ml) was mixed in a Paleozoic Era process vial. The vial was capped properly and irradiated with microwaves under pressurized conditions (17.2 bar, 90 °C) for 20 min. The reaction mixture was evaporated in vacuo and the residual solid was taken in ethanol, filtered off and dried and finally recrystallized from ethanol to afford the corresponding triazolo[1,5-a]pyrimidine (10).