Réaction #50231

Équation de réaction

water

Aluminium trichloride

1-methyl-5-(2-n-propoxyphenyl)-3-n-propyl-1,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one

2-bromoacetyl chloride

→

title compound

Rendement 60.0%

5-(5-Bromoacetyl-2-n-propoxyphenyl)-1-methyl-3-n-propyl-1,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one

Rendement 60.0%

Solvants

dichloromethane

Conditions de réaction

Traitement

1. 1
   Températureheated
2. 2
   Températureunder reflux for 3 hours
3. 3
   workup.STIRRINGThe resulting mixture was stirred for 1 hour
4. 4
   Extractionextracted with dichloromethane (2×50 ml)
5. 5
   LavageThe combined organic extracts were washed with brine (2×50 ml)
6. 6
   Séchagedried (Na2SO4)
7. 7
   Autreevaporated under vacuum
8. 8
   Autreto give an off-white solid, which
9. 9
   Autrewas triturated with ether

Mode opératoire

Aluminium trichloride (6.0 g, 0.045 mol) was added portionwise to a stirred solution of 1-methyl-5-(2-n-propoxyphenyl)-3-n-propyl-1,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one (5.0 g, 0.0153 mol) and 2-bromoacetyl chloride (2.5 ml, 0.0303 mol) in dichloromethane (100 ml) at 0° C. The reaction mixture was allowed to warm to room temperature, stirred for 18 hours, heated under reflux for 3 hours and then added cautiously to ice and water (100 g). The resulting mixture was stirred for 1 hour and extracted with dichloromethane (2×50 ml). The combined organic extracts were washed with brine (2×50 ml), dried (Na2SO4), then evaporated under vacuum to give an off-white solid, which was triturated with ether to give the title compound as a white solid (4.1 g, 60%). A small sample was crystallised from ethyl acetate-hexane to give the pure product, m.p. 136°-137° C. Found: C,53.82; H,5.24; N,12.57. C20H23BrN4O3 requires C,53.70; H,5.18; N,12.52%.

Source