Reacción #1792007

Ecuación de reacción

ethyl 6,7-dihydro-10-methoxy-4-oxo-4H-pyrimido[2,1-a]isoquinoline-3-carboxylate

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title acid

Rendimiento 81.0%

6,7-Dihydro-10-hydroxy-4-oxo-4H-pyrimido[2,1-a]isoquinoline-3-carboxylic Acid

Rendimiento 81.0%

Disolventes

hydrobromic acid

Condiciones de reacción

Tratamiento posterior

1. 1
   TemperaturaThe solution was cooled
2. 2
   Otrothe yellow product collected
3. 3
   Lavadowashed with water
4. 4
   workup.DISSOLUTIONdissolved in warm 0.5 N NaOH (80 ml.)
5. 5
   workup.ADDITIONThe basic solution was treated with decolorizing carbon
6. 6
   Filtraciónfiltered
7. 7
   LavadoThe precipitated material was washed on the
8. 8
   Filtraciónfilter successively with water, ethanol and acetone
9. 9
   Otroto give 3.5 g

Procedimiento

A solution of ethyl 6,7-dihydro-10-methoxy-4-oxo-4H-pyrimido[2,1-a]isoquinoline-3-carboxylate (5.0 g., 0.0175 mole) in 48% hydrobromic acid (125 ml.) was refluxed for 4 hours. The solution was cooled and the yellow product collected, washed with water, and dissolved in warm 0.5 N NaOH (80 ml.). The basic solution was treated with decolorizing carbon, filtered and the filtrate acidified with hydrochloric acid. The precipitated material was washed on the filter successively with water, ethanol and acetone to give 3.5 g. (81% yield) of the title acid, m.p. 326°-327°.

Fuente