Synthesis of the nitrone derivatives 3a–j^a.

Entry	Compound	Time (min)	Mp (oC)	Yieldb (%)
1		30	180–182	89
2		30	228	85
3		40	212–214	86
4		25	241–242	91
5		25	260–262	85
6		40	201–204	85
7		25	210–212	95
8		35	187–188	93
9		25	188–190	95
10		35	189–190	91

^aReaction conditions: 0.1 mmol 2-aminobenzimidazole (1) with 0.1 mmol of the aromatic aldehyde in the presence of 10 mol% Mn(NO₃)₂·6H₂O in ethanol (5 mL), addition of m-CPBA (0.12 mmol) and room temperature.

^bIsolated yield.