Icotinib (Hydrochloride)

Clinical Use

Icotinib hydrochloride, developed by the Chinese pharmaceutical company Zhejiang Bata Pharma Inc., is a potent small molecule epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor for the treatment of non-small cell lung cancer (NSCLC). It was first approved by the SFDA of China, and launched under the brand name Conmana in the middle of 2011, representing an important milestone for Chinese pharmaceutical research and development. As the third EGFR-TKI drug targeting NSCLS therapy, icotinib hydrochloride possesses a similar structure to gefitinib (Iressa, AstraZeneca) and erlotinib (Tarceva, OST & Roche). Interestingly, a randomized, double-blind phase III clinical study of icotinib versus gefitinib in 399 patients with advanced NSCLC demonstrated that icotinib provides similar efficacy to gefitinib, but with better tolerability in NSCLC patients previously treated with one or two chemotherapy agents.

Synthesis

Icotinib was prepared by a similar process approach to that of erlotinib. Beginning from commercially available 2,20-(ethylenedioxy)diethanol (162), bis-tosylation to 163, followed by bis-alkylation with commercially available catechol derivative 164 provided crown-4-ether 165 in 96% yield. Nitration of polyether 165 using concentrated nitric acid and concentrated sulfuric acid provided nitroarene 166 in 65% yield. Reduction of the nitroarene under catalytic hydrogenation conditions gave amine 167 in 85% yield. Condensation of the amine 167 with formamide in the presence of ammonium formate afforded quinazolinone 168 in 80% yield. The chlorination of 168 using POCl3 furnished quinazolyl chloride 169 in 77% yield. The treatment of chloride 169 with amine 170 followed by the HCl salt formation produced icotinib hydrochloride (XIV) in good yield.