Reaktion #323319

ord-e7dc0c87bbe247bab9fe2d1893b5eaa1

Reaktionsgleichung

[Na+].[O-]Br
sodium hypobromite
BrBr
bromine
[Na+].[OH-]
sodium hydroxide
Cl
hydrochloric acid
O=C(O)c1cccnc1O
2-hydroxy-nicotinic acid
[Na+].[OH-]
sodium hydroxide
[Na+].[O-]Br
sodium hypobromite
O=C(O)c1cc(Br)cnc1O
product
Ausbeute 63.5%
O=C(O)c1cc(Br)cnc1O
5-Bromo-2-hydroxy-3-pyridinecarboxylic acid
Ausbeute 63.5%

Lösungsmittel

Reaktionsbedingungen

Detaillierte Bedingungen
See reaction.notes.procedure_details.

Aufarbeitung

  1. 1
    Sonstigeprepared
  2. 2
    workup.ADDITIONdiluted to 400 ml
  3. 3
    workup.STIRRINGthe reaction solution was stirred for another 24 hr
  4. 4
    TemperaturThe reaction solution was cooled in an ice bath
  5. 5
    SonstigeCrystallization from isopropyl alcohol

Vorschrift

To a solution of 10 g (0.07 mole) of 2-hydroxy-nicotinic acid in 16.8 g of 50% sodium hydroxide (0.21 mole) diluted with 25 ml of water was added 200 ml of sodium hypobromite solution prepared by adding 13.6 g (0.17 mole) of bromine to a solution of 20.16 g of 50% sodium hydroxide (0.25 mole) in 125 ml of water at 0° C. diluted to 400 ml. After 24 hrs of stirring at room temperature, another 100 ml portion of the above sodium hypobromite solution was added and the reaction solution was stirred for another 24 hr. The reaction solution was cooled in an ice bath and acidified carefully with 12N hydrochloric acid. Crystallization from isopropyl alcohol gave 9.7 g (63.5%) of product. A sample was further recrystallized from 95% ethanol, m.p. 245° C.

Quelle

DOI: 10.6084/m9.figshare.5104873.v1Patent: US04642343uspto-grants-1987_02