2-Chloro-3-Nitro-6-Trifluoromethyl Pyridine synthesis

Yield:117519-08-1 36%

Reaction Conditions:

Stage #1:3-amino-2-chloro-6-(trifluoromethyl)pyridine with fuming sulphuric acid;dihydrogen peroxide in water at 0 - 25; for 20 h;
Stage #2: with ammonia in water

Steps:

5
To a cooled (0 °C) mixture of fuming sulfuric acid (3.2 mL) and aqueous hydrogen peroxide (50%, 1.6 mL) was added a solution of 3-amino-2-chloro-6-(trifluoromethyl)pyridine (304 mg, 1.55 mmol) in cone, sulfuric acid (4 mL). The reaction was slowly warmed to 25 °C and stirred 20 hours, whereupon the reaction mixture was poured into ice water. The mixture was neutralized with aqueous ammonium hydroxide, and then extracted with ethyl acetate (5 X 10 mL).The organic layers were dried over anhydrous sodium sulfate and concentrated to afford compound 5.1 (126 mg, 36%) as a yellow solid that was used without further purification.

References:

SUNESIS PHARMACEUTICALS, INC. WO2006/65703, 2006, A1 Location in patent:Page/Page column 107

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