Table 3 Synthesis of spiro[indoline-3,4′- pyrano[2,3-c]pyrazole] derivatives using Fe3O4@l-arginine under solvent-free conditions
Entry | Product | Yield (%)a | M.p. °C | Lit. M.p. °C |
|---|---|---|---|---|
1 | 5{1,1,1,1} | 96 | 286–288 | 285–286 [18] |
2 | 5{1,1,2,1} | 91 | 297–298 | 297–298 [18] |
3 | 5{1,1,3,1} | 95 | 283–285 | 282–283 [18] |
4 | 5{2,1,1,1} | 90 | 225–227 | 227–229 [18] |
5 | 5{1,2,3,1} | 91 | 257–259 | 256–257 [18] |
6 | 5{1,2,1,1} | 90 | 282–284 | 280–281 [18] |
7 | 5{1,2,1,2} | 87 | 240–242 | 242–243 [18] |
8 | 5{1,2,3,2} | 89 | 256–258 | 257–259 [18] |
9 | 5{1,2,2,2} | 85 | 266–268 | 265–267 [18] |
10 | 5{1,1,4,1} | 94 | 278–280 | 279–281 [18] |
11 | 5{1,2,4,1} | 86 | 246–248 | 247–249 [18] |
12 | 5{1,2,4,2} | 87 | 262–264 | 260–263 [18] |
13 | 5{2,1,4,1} | 89 | 220–222 | 222–224 [18] |
14 | 5{2,1,3,2} | 92 | 212–214 | –b |
15 | 5{2,1,2,2} | 90 | 279–281 | –b |
16 | 5{2,1,4,2} | 97 | 198–200 | –b |