Reaktion #670454

Reaktionsgleichung

ammonium hydroxide

isopropanol-HCl

sulfuric acid

1,2,3,5,6,10b-hexahydropyrrolo[2,1-a]isoquinoline

potassium nitrate

→

solid

9-Nitro-1,2,3,5,6,10b-hexahydropyrrolo[2,1-a]isoquinoline hydrochloride

Lösungsmittel

isopropanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONAfter addition
2. 2
   workup.ADDITIONpoured onto ice
3. 3
   ExtraktionThe product was extracted twice with dichloromethane
4. 4
   TrocknenThe dried (magnesium sulfate) organic phase
5. 5
   Einengenwas concentrated
6. 6
   Sonstigeto give a red oil which
7. 7
   SonstigeThe resulting precipitate was collected

Vorschrift

To concentrated sulfuric acid (200 ml) at -10° C. was added portionwise 1,2,3,5,6,10b-hexahydropyrrolo[2,1-a]isoquinoline (20.5 g, 118 mmol) over 2 h. After addition was complete, potassium nitrate (1 1.6 g, 0.115 mol) was added portionwise over 3 h. The reaction mixture was stirred for an additional 3 h and then poured onto ice and made basic with concentrated ammonium hydroxide. The product was extracted twice with dichloromethane. The dried (magnesium sulfate) organic phase was concentrated to give a red oil which was immediately dissolved in isopropanol (200 ml) and made acidic with saturated isopropanol-HCl. The resulting precipitate was collected to give a tan solid (18.9 g). Recrystallization from 95% ethanol (100 ml) afforded the title compound as an off-white solid (11.5 g, 62%), m.p. 243-5° C. This was converted to the free base by dissolving in water, making basic with dilute base, and extracting with dichloromethane to give 96% recovery of the product.

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