Substrate scope for the 2-amino-4H-benzo[b]pyran derivatives^a.

Entry	Products	Time (min)	Yieldb (%)	Mp (°C)
				Found reported
1		15	95	229–231, 231–233 (ref. 47)
2		12	89	212–214, 215–217 (ref. 47)
3		12	91	216–217, 218–220 (ref. 47)
4		7	96	223–225, 225–226 (ref. 47)
5		7	95	178–180, 180–182 (ref. 47)
6		30	90	221–223, 220–222 (ref. 47)
7		35	89	201–203, 198–200 (ref. 47)
8		12	88	192–194, 190–192 (ref. 47)
9		30	90	221–223, 222–224 (ref. 47)
10		35	93	180–182, 182–184 (ref. 47)
11		15	92	152–154, 155–157 (ref. 47)
12		20	89	212–214, 215–217 (ref. 47)
13		15	92	216–218, 215–217 (ref. 47)
14		7	91	223–225, 224–226 (ref. 47)
15		20	89	178–179, 180–181 (ref. 47)
16		20	90	246–248, 248–250 (ref. 47)

^aReaction conditions: various aldehydes (1 mmol), dimedone (1 mmol), malononitrile (1 mmol), catalysts (0.07 g) under the dry grinding method at room temperature.

^bIsolated pure yield.