Substrate scope of the synthesis of multi-substituted pyrazoles^a.

Entry	1 (R1, R2)	2 (Ar)	Product, yieldb
1	Ph, Ph	4-BrC6H4	3a, 54%; 4a, 29%
2	Ph, Ph	4-ClC6H4	3b, 59%; 4b, 28%
3	Ph, Ph	4-OMeC6H4	3c, 48%; 4c, 27%
4	3-FC6H4, Ph	4-BrC6H4	3d, 57%; 4d, 24%
5	3-FC6H4, Ph	4-ClC6H4	3e, 59%; 4e, 22%
6	3-FC6H4, Ph	4-OMeC6H4	3f, 50%; 4f, 25%
7	4-FC6H4, Ph	4-ClC6H4	3g, 55%; 4g, 27%
8	4-FC6H4, Ph	4-BrC6H4	3h, 50%; 4h, 27%
9	3-ClC6H4, Ph	4-ClC6H4	3i, 54%; 4i, 27%
10	3-ClC6H4, Ph	4-BrC6H4	3j, 44%; 4j, 29%
11	3-ClC6H4, 4-OMeC6H4	4-OMeC6H4	3k, 52%; 4k, 29%
12	2-BrC6H4, 4-OMeC6H4	4-ClC6H4	3l, 48%; 4l, 47%
13	2-Np, 4-OMeC6H4	4-ClC6H4	3m, 56%; 4m, 30%
14	2-Np, 4-OMeC6H4	4-OMeC6H4	3n, 54%; 4n, 32%
15	2-Np, Ph	4-ClC6H4	3o, 54%; 4o, 31%
16	3-FC6H4, 2,4,6-triMeC6H2	4-ClC6H4	3p, 67%; 4p, 29%
17	4-FC6H4, 2,4,6-triMeC6H2	4-ClC6H4	3q, 65%; 4q, 30%
18	4-FC6H4, 2,4,6-triMeC6H2	4-OMeC6H4	3r, 60%; 4r, 28%
19	2-Thiophenyl, Ph	4-ClC6H4	3s, 59%; 4s, 21%
20	Ph, Ph	4-NO2C6H4	3t, 52%; 4t, 24%
21	Ph, 3-CF3C6H4	4-NO2C6H4	3u, 45%; 4u, 29%

^aThe reaction of 1 (0.2 mmol) with 2 (0.24 mmol) was carried out in the presence of K₂CO₃ (0.5 mmol) in EtOH (2.5 mL) at room temperature for 12 h.

^bIsolated yield.