A Novel Four-Component Reaction between Secondary Amines and Hydroxybenzaldehydes with Isocyanides in Water: An Efficient One-Pot and Green Synthesis of Benzo[b]furan Derivatives

Table 1

Condition and yield of reactions for synthesis of benzo[b]furan derivatives, 7a–i, in water.

Entry	Products	R′	R	X	Yield (%)
1	7a	1,1,3,3-Tetramethylbutyl	Benzyl	NO2	90
2	7b	Cyclohexyl	Benzyl	NO2	98
3	7c	1,1,3,3-Tetramethylbutyl	Ethyl	NO2	81
4	7d	Cyclohexyl	Ethyl	NO2	89
5	7e	1,1,3,3-Tetramethylbutyl	Methyl	NO2	42
6	7f	Cyclohexyl	Methyl	NO2	90
7	7g	1,1,3,3-Tetramethylbutyl	Benzyl	Br	48
8	7h	Cyclohexyl	Benzyl	Br	91
9	7i	1,1,3,3-Tetramethylbutyl	Ethyl	Br	80