6-Iodo-1H-indazole

Light yellow to Brown powder to crystal

6-Iodo-1H-indazole is an intermediate used to synthesize inhibitors of Chk1.

[1] NOOLVI M N, PATEL H M. Small Molecule Tyrosine Kinase Inhibitors: The New Dawn for Cancer Therapy[J]. Letters in Drug Design & Discovery, 1900, 9(1): 84-125. DOI:10.2174/157018012798192892.

Revill P. and co-worker synthesized Axitinib by iodination of 6-iodo-1H-indazole (100) to give 3,6-di iodo- 1H-indazole (101) ,which on further reaction with 2- mercapto-N-methylbenzenesulfinamide gives 2-(3-iodo-1Hindazol-6-ylthio)-N-methylbenzamide (101), the same can be obtained via 2-(1H-indazol-6-ylthion)-N-methylbenzamide (102) starting from 6-iodo-1H-indazole (100) through alternative route. N-protection of 2-(3-iodo-1H-indazol-6- ylthio)-N-methylbenzamide (101) by Boc2, DMAP or DHP, TsOH gives respective N-protected intermediates 103, 104. Further treatment of 103, 104 with 2-vinyl pyridine give rise to N-protected-2-(1-methyl-3-(2-(pyridine-2-yl) vinyl)-1Hindazole-6-ylthio) benzothioamide 105 and 106. Deprotection of 105 and 106 gives destination compound axitinib (107), the same can be obtained without protection from 2-(3-iodo-1H-indazol-6-ylthio)-N-methylbenzamide (101) by simple reaction with 2-vinyl pyridine^[1].