Optimization of ultrasound-assisted-one-pot synthesis of 3-substituted-isoindolin-1-ones^a.

Entry	[NaBH3CN] (equiv.)	Solvent	Catalyst	Yieldb (%)
1	3	i-PrOH	p-TSA	63
2	5	i-PrOH	p-TSA	70
3	10	i-PrOH	p-TSA	86
4	15	i-PrOH	p-TSA	75
5	10	DMSO	p-TSA	79
6	10	MeCN	p-TSA	90
7	10	THF	p-TSA	77
8	10	MeCN	HCl	72
9	10	MeCN	TFA	93
10	10	MeCN	BF3·OEt2	80
11c	10	MeCN	TFA	77

^aThe experiments were performed using 0.5 mmol of 2a and 1.0 mmol of 3a under ultrasonic irradiation (40 kHz, 350 W) for 30 min (1st step) + 60 min (2nd step).

^bIsolated yields.

^cThe reaction was performed at 50 °C for 5 h + 5 h using conventional heating.