Methyl 5-chloro-6-methoxypyridine-3-carboxylate → HCID 67026916, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 5-chloro-6-methoxy-nicotinic acid methyl ester (880 mg, 4.37 mmol) and 2,4,6-tri-(2-methyl-propenyl)-cycloboroxane pyridine complex (1.42 g, 4.37 mmol, prepared in analogy to a procedure given by F. Kerins, D. F. O'Shea J. Org. Chem. 67 (2002) 4968-4971) in dioxane (10 mL) and 2 M aq. K2CO3 solution (5 mL), Pd(PPh3)4 (101 mg, 87 μmol) is added after the mixture has been degassed and put under N2. The mixture is stirred at 80° C. for 18 h before it is cooled to rt, diluted with EA and washed with water. The org. extract is dried over MgSO4, filtered and concentrated. The crude product is purified by CC on silica gel eluting with heptane:EA 4:1 to give 6-methoxy-5-(2-methyl-propenyl)-nicotinic acid methyl ester (300 mg) as a colourless oil; LC-MS: tR=1.01 min; [M+1]+=222.00; 1H NMR (CDCl3): δ 1.85 (d, J=1.3 Hz, 3H), 1.97 (d, J=1.0 Hz, 3H), 3.93 (s, 3H), 4.04 (s, 3H), 6.20 (s, 1H), 8.04 (d, J=2.0 Hz, 1H), 8.71 (d, J=2.3 Hz, 1H).

Provenance & Evidence