To a solution of 2,6-dichloroisonicotinic acid (2 g, 10.4 mmol) in toluene (50 mL) N, N- dimethylformamide di-fert-butil acetal (15 mL, 62.5 mmol) was added under nitrogen atmosphere and mixture heated at 80°C overnight. Ethyl acetate was added, and the organic layer was washed with water and brine, dried (MgS04), filtered and concentrated to yield tert-Butyl 2,6-dichloroisonicotinate (2.34 g, 87 per cent) as a solid.
[1] Patent: WO2008/11499, 2008, A1. Location in patent: Page/Page column 37-38
[2] Organic Process Research and Development, 2009, vol. 13, # 6, p. 1145 - 1155
[3] Patent: WO2010/111058, 2010, A1. Location in patent: Page/Page column 79
