Ethyl Acetate → 3-amino-6-trifluoromethyl-3',6'-dihydro-2'H-[2,4']bipyridinyl-1'-carboxylic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

A solution of 3-amino-2-chloro-6-trifluoromethyl-pyridine (0.890 g), 4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-3,6-dihydro-2H-pyridine-1-carboxylic acid tert-butyl ester (1.4 g) (prepared as described in WO 2006/003494) and tetrakis(triphenyl-phosphine)palladium (0.200 g) in 1,2-dimethoxyethane (45 ml) was treated with aqueous potassium phosphate (1.1 M) (1.92 g). The reaction mixture was stirred at 80° C. for 3 hours. Aqueous workup with ethyl acetate furnished a residue which was purified by chromatography on silica gel (eluent: hexane/ethyl acetate 1:1) to give 3-amino-6-trifluoromethyl-3′,6′-dihydro-2′H-[2,4′]bipyridinyl-1′-carboxylic acid tert-butyl ester (1.5 g) as a white solid. MS (ES+) 288 (M-isoprene); 1H NMR (400 MHz, CDCl3) 1.50 (s, 9H), 2.61 (m, 2H), 3.67 (t, 2H), 4.10 (m, 2H), 4.21 (s, 2H), 6.11 (s, 1H), 7.03 (d, 1H), 7.33 (d, 1H).

Provenance & Evidence