Reaktion #337587

Reaktionsgleichung

7-bromo-1,4-dihydroxy-isoquinoline-3-carboxylic acid butyl ester

Phosphorous oxychloride

→

product

Ausbeute 43.5%

7-Bromo-1-chloro-4-hydroxy-isoquinoline-3-carboxylic acid butyl ester

Ausbeute 43.5%

Lösungsmittel

acetonitrile

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturat reflux for 4 h
2. 2
   TemperaturAfter cooling
3. 3
   Einengenthe mixture was concentrated
4. 4
   workup.ADDITIONEthyl acetate mixture was poured into saturated sodium bicarbonate solution
5. 5
   workup.STIRRINGwith efficient stirring for 1 h
6. 6
   SonstigeTwo phases were separated
7. 7
   ExtraktionAqueous layer was extracted with ethyl acetate
8. 8
   TrocknenCombined organic layer was dried over magnesium sulfate
9. 9
   Filtrationfiltered
10. 10
    Einengenconcentrated
11. 11
    SonstigeCrude product was purified by silica gel chromatography
12. 12
    Wascheneluting with methylene chloride

Vorschrift

170 mg (0.5 mmol) of 7-bromo-1,4-dihydroxy-isoquinoline-3-carboxylic acid butyl ester (from Example D-21 c) was dissolved in 2 ml of anhydrous acetonitrile. Phosphorous oxychloride (536 mg, 3.5 mmol) was added and the resulting mixture was stirred at reflux for 4 h. After cooling, the mixture was concentrated and the residue was taken into ethyl acetate. Ethyl acetate mixture was poured into saturated sodium bicarbonate solution with efficient stirring for 1 h. Two phases were separated. Aqueous layer was extracted with ethyl acetate. Combined organic layer was dried over magnesium sulfate, filtered and concentrated. Crude product was purified by silica gel chromatography eluting with methylene chloride to give 78 mg of product as white solid. MS-(+)-ion: M+1=359.96, 357.98

Quelle