To a solution of 2-chloro-6-dimethylamino-isonicotinic acid tert-butyl ester (770 mg, 3.00 mmol) in dioxane (45 mL), Cs2CO3 (1270 mg, 3.90 mmol) followed by P(tert.-Bu)3 (30 mg, 0.15 mmol) and 2,4,6-trivinylcyclotriboroxane pyridine complex (722 mg, 3.00 mmol, prepared according to F. Kerins, D. F. O'Shea J. Org. Chem. 67 (2002) 4968-4971) is added. The mixture is degassed and put under argon before Pd2(dba)3 (82 mg, 0.09 mmol) is added. The mixture is stirred at 100° C. for 15 h before it is cooled to rt and filtered over a short silica gel pad eluting with DCM. The filtrate is concentrated and purified on prep. TLC plates with DCM to give 2-dimethylamino-6-vinyl-isonicotinic acid tert-butyl ester (885 mg) as a red to brownish resin; LC-MS: tR=0.82 min, [M+1]+=249.37.
