Dabrafenib Mesylate

Description

Dabrafenib mesylate, sold by GlaxoSmithKline under the trade name Tafinlar, was approved by the U.S. FDA in May 2013 for the treatment of metastatic BRAF-mutant melanoma. Dabrafenib reversibly inhibits the BRAF(V600E) mutant kinase as a selective ATP-competitive inhibitor which results in tumor regression.

The Uses of Dabrafenib Mesylate

Dabrafenib is an inhibitor of mutated BRAF kinase and has clinical activity with a manageable safety profile in clinical trials of phase 1 and 2 in patients with BRAF(V600)-mutated metastatic melanoma.

Definition

ChEBI: A methanesulfonate (mesylate) salt prepared from equimolar amounts of dabrafenib and methanesulfonic acid. Used for treatment of metastatic melanoma.

Synthesis

Commercially available fluoroaniline 40 was first converted to sulfonamide 42 in 91% yield by treatment with 2,5-difluorobenzenesulfonyl chloride (41) in the presence of pyridine. Next, deprotonation of 2-chloro-4-methylpyrimidine (43) with lithium bis(trimethylsilyl)amide (LHMDS) followed by addition to ester 42 afforded chloropyrimidine 44 in 72% yield. Bromination followed by thiazole formation through the use of 2,2-dimethylpropanethioamide gave the penultimate target 45 in 80% over two steps. Chloropyrimidine 45 was subjected to SNAr conditions with ammonium hydroxide to furnish the aminopyrimidine in 88% yield, and this was followed by exposure to methanesulfonic acid to afford dabrafenib mesylate (VI) in 85% yield.

Storage

Store at -20°C

References

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[4]ma xh, piao sf, dey s, mcafee q, karakousis g, villanueva j, hart ls, levi s, hu j, zhang g, lazova r, klump v, pawelek jm, xu x, xu w, schuchter lm, davies ma, herlyn m, winkler j, koumenis c, amaravadi rk. targeting er stress-induced autophagy overcomes braf inhibitor resistance in melanoma. j clin invest. 2014; 124(3): 1406-17.