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ChemicalBook CAS DataBase List 2,6-Dichloro-5-fluoronicotinic acid
82671-06-5

2,6-Dichloro-5-fluoronicotinic acid synthesis

5synthesis methods
ethyl 2,6-dichloro-5-fluoropyridine-3-carboxylate

82671-03-2

2,6-Dichloro-5-fluoronicotinic acid

82671-06-5

The general procedure for the synthesis of 2,6-dichloro-5-fluoropyridine-3-carboxylic acid from ethyl 2,6-dichloro-5-fluoropyridine-3-carboxylate is as follows: Example 1: 1. ethyl 2,6-dichloro-5-fluoropyridine-3-carboxylate (20 g, 84 mmol) was dissolved in a mixture of 40 mL of trifluoroacetic acid and 40 mL of 7.5N hydrochloric acid. 2. The mixture was heated to reflux and kept reacting for 24 hours. 3. Upon completion of the reaction, the solution was cooled and the trifluoroacetic acid was removed by evaporation under reduced pressure. 4. After cooling to room temperature, 100 mL of water was added, at which point a white precipitate formed in the solution. 5. The precipitate was collected by filtration, washed with hexane, and dried to give 12.91 g (73.2% yield) of 2,6-dichloro-5-fluoropyridine-3-carboxylic acid, with a melting point of 153-154 °C. The reaction was completed with the addition of 100 mL of water.

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Yield:82671-06-5 12.91 g (73.2%)

Reaction Conditions:

with trifluoroacetic acid in water;

Steps:

1 1-o,p-Difluorophenyl-6-fluoro-1,4-dihydro-4-oxo-7-(3-amino pyrrolidin-1-yl)-1,8-naphthyridine-3-carboxylic acid hydrochloride salt

Example 1 1-o,p-Difluorophenyl-6-fluoro-1,4-dihydro-4-oxo-7-(3-amino pyrrolidin-1-yl)-1,8-naphthyridine-3-carboxylic acid hydrochloride salt Ethyl 2,6-dichloro-5-fluoronicotinate (20 g, 84 mmol) was dissolved in a mixture of 40 mL of trifluoroacetic acid and 40 mL of 7.5 N HCI. The mixture was heated to reflux for 24 hours. The solution was cooled, and the trifluoroacetic acid was removed by evaporation under reduced pressure. Upon cooling, 100 mL of water was added and a white precipitate formed. The precipitate was filtered, washed with hexane, and dried, yielding 12.91 g (73.2%) of 2,6-dichloro-5-fluoronicotinic acid: mp 153-154°C.

References:

EP302372,1989,A1

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