Water → 3-Amino-6-chloro-4-methylpicolinic acid

HRID 887715Notes

Reaction equation

C(OC(=O)[NH:7][C:8]1[C:9]([C:16]#N)=[N:10][C:11]([Cl:15])=[CH:12][C:13]=1[CH3:14])(C)(C)C.[OH2:19].[OH-:20].[Na+]>S(=O)(=O)(O)O>[NH2:7][C:8]1[C:9]([C:16]([OH:20])=[O:19])=[N:10][C:11]([Cl:15])=[CH:12][C:13]=1[CH3:14]

Participants

Conditions

Temperature: 100 °C

Procedure

(6-Chloro-2-cyano-4-methyl-pyridin-3-yl)-carbamic acid tert-butyl ester (3.72 g) was dissolved in concentrated sulfuric acid (19 mL) and stirred for 1 h at 100° C. The reaction mixture was cooled to room temperature and water (19 mL) was slowly added. The reaction mixture was warmed again to 100° C. and stirred at this temperature for 2 h. Water was added after cooling to room temperature, the mixture was cooled in an ice bath and the pH was adjusted to ˜14 by slow addition of solid sodium hydroxide. The aqueous solution was washed 2× with MTB-ether, the aqueous layer was then adjusted to pH ˜2 by addition of 5 M hydrochloric acid and extracted 3× with ethyl acetate. The combined organic layer was washed with brine, dried over magnesium sulfate and concentrated in vacuum to afford 2.25 g of the title compound of the formula

Workup

temperatureThe reaction mixture was cooled to room temperature
temperatureThe reaction mixture was warmed again to 100° C.
stirringstirred at this temperature for 2 h
temperatureafter cooling to room temperature
temperaturethe mixture was cooled in an ice bath
washThe aqueous solution was washed 2× with MTB-ether
additionthe aqueous layer was then adjusted to pH ˜2 by addition of 5 M hydrochloric acid
extractionextracted 3× with ethyl acetate
washThe combined organic layer was washed with brine
dry with materialdried over magnesium sulfate
concentrationconcentrated in vacuum

Sources & evidence

ORD record: ord-e41ac4c2b7d74a53a3be901dac67fe09
Source dataset: uspto-grants-2012_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08247431B2

Reaction notes

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