Ethyl Acetate → 1,1-Dimethylethyl 2-(2,6-dichloro-5-fluoro-4-pyrimidinyl)hydrazinecarboxylate

Participants

Reaction Steps

2,4,6-Trichloro-5-fluoropyrimidine (20.92 g, 104.1 mmol) was dissolved in THF (300 mL) at room temperature and stirred. To this stirring solution was added t-butyl carbazate (13.74 g, 104.1 mmol), followed by diisopropylethylamine (19.0 mL, 109.3 mmol). The reaction mixture turned light yellow, and after several minutes a precipitate formed. The reaction appeared complete after 1.5 h, as monitored by TLC (10% EtOAc/Hex). The reaction mixture was concentrated in vacuo to remove most of the THF, and the residue was dissolved in CH2Cl2 (˜400 mL). The solution was washed with ˜400 mL of sat. aq. NH4Cl. The organics were dried and concentrated to give a pale yellow solid (31.37 g). LCMS: (M+H+2Na-Boc)+: 241.

Provenance & Evidence