2,5-Dichloroisonicotinic acid

White to yellow to brown solid

2, 5-Dichloro-4-pyridinecarboxylic acid was prepared according to known procedures (see Eur. J. Org. Chem. 2001, 1371-1376), as follows: At -75 °C, 2, 5-dichloropyridine (3.7 g, 25 mmol) was added to a solution of butyllithium (1.6M in hexane) (25 mmol) and N, N, N, N, N- pentamethyldiethylenetriamine (5.3 mL, 4.3 g, 25 mmol) in tetrahydrofuran (50 mL). After 2 h at - 75 °C, the mixture was poured onto an excess of freshly crushed dry ice. Water (50 mL) was10 added, the aqueous phase decanted and washed with diethyl ether (3 x 20 mL) and neutralized with 5N HCl to pH 1. The precipitate was filtered and washed with water to give 2.7g of white solid as a pure product. The filtrate was extracted with ethyl acetate and the combined organic layers were evaporated to dryness. The residue was recrystallized from ethanol to give another batch of pure product. (The filtrate was evaporated to small volume and the precipitate was filtered and washed15 with water to give another batch of product); m.p. 227-229 °C (from ethanol); 4.2 g (87percent).[00294] 1H NMR (400MHz, DMSO-d6): a 14.43 (brs, 1H, exchangeable with D2O), 8.64 (s, 1 H), 7.87 (s, 1 H).[00295]2-(2, 5-DicHoro-pyridke-4-carb.infin.yl)-3 2, 5-Dichloropyridine was added to a THF solution of n-BuLi and PMDTA and stirred for 2 hours at -782, 5-Dichloro-4-pyridinecarboxylic acid was prepared according to known procedures (see Eur. J. Org. Chem. 2001, 1371-1376), as follows: At -75 °C, 2, 5-dichloropyridine (3.7 g, 25 mmol) was added to a solution of butyllithium (1.6M in hexane) (25 mmol) and N, N, N, N, N- pentamethyldiethylenetriamine (5.3 mL, 4.3 g, 25 mmol) in tetrahydrofuran (50 mL). After 2 h at - 75 °C, the mixture was poured onto an excess of freshly crushed dry ice. Water (50 mL) was10 added, the aqueous phase decanted and washed with diethyl ether (3 x 20 mL) and neutralized with 5N HCl to pH 1. The precipitate was filtered and washed with water to give 2.7g of white solid as a pure product. The filtrate was extracted with ethyl acetate and the combined organic layers were evaporated to dryness. The residue was recrystallized from ethanol to give another batch of pure product. (The filtrate was evaporated to small volume and the precipitate was filtered and washed15 with water to give another batch of product); m.p. 227-229 °C (from ethanol); 4.2 g (87percent).[00294] 1H NMR (400MHz, DMSO-d6): a 14.43 (brs, 1H, exchangeable with D2O), 8.64 (s, 1 H), 7.87 (s, 1 H).[00295]2-(2, 5-DicHoro-pyridke-4-carb.infin.yl)-32, 5-Dichloropyridine was added to a THF solution of n-BuLi and PMDTA and stirred for 2 hours at -780C before quenching with dry ice. The product was isolated by acid-base work-up in 47percent yield.a) 2, 5-Dichloropyridine-4-carboxylic acidAt -75 C, 2, 5-dichloropyridine (3.7g) was added to a solution of butyl lithium (25 ml, IM) and N, N, N, N, N-pentamethyldiethylenetriamine (5.3 ml) in THF (50 ml) under a nitrogen atmosphere at -75 C and the reaction mixture stirred for 2 h, poured onto dry ice, and water (50ml) added. The aqueous phase was washed with diethyl ether; acidified to pH 2 and the white solid filtered off dried to give the product (2.5g), a known compound, for the next reaction, without further characterization other than ascertaining that the compound was one spot by tic with the expected molecular weight (M-I) of 190.

Molecular Weight:192.00
XLogP3:2
Hydrogen Bond Donor Count:1
Hydrogen Bond Acceptor Count:3
Rotatable Bond Count:1
Exact Mass:190.9540837
Monoisotopic Mass:190.9540837
Topological Polar Surface Area:50.2
Heavy Atom Count:11
Complexity:165
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes