Table 3.

Comparison of microwave-assisted synthesis of tetrahydroquinoline under standard reaction conditions.

Compound	R1	R2	Microwave Heating		Conventional heating
			Time	Yield (%)	Time	Yield (%)
3		p-SO2NH2	10 min	60	48 h	22 (ref:7)
4		p-SO2NH2	15 min	66	24 h	2 (ref:7)
5		p-SO2NH2	15 min	90	24 h	20 (ref:7)
6		p-SO2NH2	10 min	61	48 h	19 (ref:7)
7		p-SO2NH2	15 min	67	24 h	30 (ref:6)
8		p-SO2NH2	15 min	66	12 h	13 (ref:7)
9		p-SO2NH2	15 min	67	–	–
10		o-SO2NH2	15 min	55	–	–
11		p-COCH3	15 min	74	2 h	98 (ref: 3)
12		p-SO2NH2	15 min	40	–	–
13		p-OMe	10 min	58	–	–
14		p-Br	10 min	56	–	–
15	–H	p-SO2NH2	15 min	48	–	–
16		p-COOH	15 min	65	–	–