Diisopropylethylamine → tris(1,1-dimethylethyl)2-{2-chloro-6-[(2R)-2,4-dimethyl-1-piperazinyl]-5-fluoro-4-pyrimidinyl}-1,1,2-hydrazinetricarboxylate

Participants

Reaction Conditions

Reaction Steps

To (3R)-1,3-dimethylpiperazine dihydrochloride (102.22 g, 546.3 mmol) was added a solution of tris(1,1-dimethylethyl)2-(2,6-dichloro-5-fluoro-4-pyrimidinyl)-1,1,2-hydrazinetricarboxylate (271.71 g, 546.3 mmol) in DMF (900 mL). The mixture was cooled to 0° C., and N,N-diisopropylethylamine (295 mL, 1694 mmol) was added. The solution was stirred and warmed to room temperature overnight. The solution was then diluted with Et2O (1000 mL) and washed with water (1000 mL). The aqueous phase was extracted with a fresh portion of Et2O (1000 mL), and the combined organic phase was washed with water (2×500 mL). The organic phase was then diluted with DCM (1000 mL), dried over anhydrous Na2SO4, filtered, and concentrated in vacuo. The residue was filtered through a silica gel plug (30% EtOAc in hexanes; 1% Et3N). The solution was then concentrated in vacuo, and the residue was azeotroped with MeOH. The residue was diluted with MeOH (1000 mL), and crystallized by addition of water. The resulting solid was collected by vacuum filtration and washed with 10% MeOH in water. The resulting yellow solid was dried at 50° C. under high vacuum to give tris(1,1-dimethylethyl)2-{2-chloro-6-[(2R)-2,4-dimethyl-1-piperazinyl]-5-fluoro-4-pyrimidinyl}-1,1,2-hydrazinetricarboxylate (257.34 g, 82% yield) as a light yellow solid. LCMS: (M+H)+: 575.2.

Provenance & Evidence