Table 1.

Screening of solvents, reaction time and temperature for the synthesis of 7b

Base	Conditiona	Temp (°C)	Time (mins)	Yield b (%)
-	No solvent	90	15	Trace
-	Ethanol	90	15	Trace
Piper idene	Ethanol	90	15	80
TMP	Ethanol	90	15	96
TMP	No solvent	90	15	Trace
DBU / pyrid ine	Ethanol	90	20	20
TMP	Acetonitrile	90	15	76
TMP	Acetonitrile	130	15	15
DBU	Acetonitrile	90	30	Trace
TMP	DMF	90	15	45
	DMF	90	30	10
NMP
DBU	DMF	120- 140	15	Trace
TMP	Water	90	15	Trace
TMP	Water	130	15	Trace
-	Water	130	30	Trace
TMP	Toluene	90	15	Trace
TMP	Isopropanol	90	15	45
TMP	THF	90	15	38
TMP	n-Butanol	90	15	33

^aAll the reaction was carried out in equimolar amount of each compound in 2 ml of solvent at 150 psi pressure.

^bIsolated yield