Table 1.

CBB-3CR involving tert-butylisocyanide.

Entry	Starting materials				Method	Product	Yield, %
	Aldehydes	R1	Aminopyrazoles	R2
1	1a	H	2a	4-F	A	4a	54
2	1b	2-CH3O	2a	4-F	A	4b	75
3	1c	3-CH3O	2a	4-F	A	4c	77
4	1d	4-CH3O	2a	4-F	A	4d	75
5	1e	4-Cl	2a	4-F	A	4e	72
6	1b	2-CH3O	2b	3-F	A	4f	83
7	1d	4-CH3O	2b	3-F	A	4g	64
8	1e	4-Cl	2b	3-F	A	4h	89
9	1b	2-CH3O	2c	2-CH2CH3	A	4i	82
10	1d	4-CH3O	2c	2-CH2CH3	A	4j	64
11	1e	4-Cl	2c	2-CH2CH3	A	4k	66
12	1b	2-CH3O	2d	4-CH2CH3	A	4l	85
13	1e	4-Cl	2d	4-CH2CH3	A	4m	53
14	1f	4-CO2CH3	2a	4-F	B	4n	85
15	1g	4-NO2	2a	4-F	B	4o	87
16	1h	4-CN	2a	4-F	B	4p	90
17	1f	4-CO2CH3	2b	3-F	B	4q	88
18	1g	4-NO2	2b	3-F	B	4r	87
19	1h	4-CN	2b	3-F	B	4s	82
20	1f	4-CO2CH3	2c	2-CH2CH3	B	4t	61
21	1g	4-NO2	2c	2-CH2CH3	B	4u	79
22	1h	4-CN	2c	2-CH2CH3	B	4v	83