Sodium borohydride → 4-(Cyclopropanecarbonyl)-6-hydroxy-1-(2-phenylethyl)piperazin-2-one

HRID 1248275Notes

Reaction equation

HRID 1248275 reaction equation
[CH:1]1([C:4]([N:6]2[CH2:11][C:10](=[O:12])[NH:9][C:8](=[O:13])[CH2:7]2)=[O:5])[CH2:3][CH2:2]1.C[O-].[Na+].[CH2:17]([C:19]1[CH:34]=[C:33](C)[CH:32]=[CH:31][C:20]=1S(OC1C=CC=CC=1)(=O)=O)[CH3:18].[BH4-].[Na+]>CC(N(C)C)=O.C(O)C.[Cl-].[Mn+2].[Cl-]>[CH:1]1([C:4]([N:6]2[CH2:11][C:10](=[O:12])[N:9]([CH2:18][CH2:17][C:19]3[CH:34]=[CH:33][CH:32]=[CH:31][CH:20]=3)[CH:8]([OH:13])[CH2:7]2)=[O:5])[CH2:2][CH2:3]1

Participants

8

Reactant 4

HCID 4311764Sodium borohydrideHCID 10942334Sodium MethoxideHCID 202792424-(Cyclopropanecarbonyl)piperazine-2,6-dioneHCID 54213395HCID 54213395, compound

Product 1

HCID 202792474-(Cyclopropanecarbonyl)-6-hydroxy-1-(2-phenylethyl)piperazin-2-one

Reagents, catalysts & solvents 3

HCID 10313134Manganese(2+) dichlorideCatalystHCID 702EthanolSolventHCID 31374DimethylacetamideSolvent2×

Procedure

0.067 mol of 4-(cyclopropylcarbonyl)-2,6-dioxopiperazine are dissolved in 200 ml of dimethylacetamide. 0.073 mol of sodium methylate are added and the mixture is left for 1 hour at ambient temperature. To the reaction medium is added, dropwise and in an inert atmosphere, a solution of 0.081 mol of (2-ethyl tosyloxy)-benzene in 50 mol of dimethylacetamide and the mixture is brought to 90° C. for 4 hours. It is evaporated to dryness under reduced pressure, the residue is taken up in a mixture of water and methylene chloride and the decanted organic phase is dried over dry sodium sulphate. The solvent is evaporated and the residue, formed by crude 4-(cyclopropylcarbonyl)-2,6-dioxo-1-phenethyl piperazine, is dissolved in 600 ml of ethanol. The solution as thus obtained has added thereto, at 0° C. and in an inert atmosphere, 0.059 mol of manganese chloride and is left for 1 hour at 0° C. 0.23 mol of sodium borohydride is added in portions to the reaction medium, kept at 0° C., and the reaction medium is left for 45 minutes at 0° C. The excess of reducing agent is destroyed by adding acetone. The insoluble salts are filtered, the filtrate is evaporated to dryness and the residue is treated with a mixture of water and methylene chloride. The decanted organic phase is dried over dry sodium sulphate and evaporated to dryness. The residue is purified by filtration on a silica bed and the product as thus obtained, formed by the 4-(cyclopropylcarbonyl)-2-hydroxy-6-oxo-1-phenethyl piperazine, is added in portions to 150 ml of hydrochloric acid previously cooled to 0° C. After one night at ambient temperature, the reaction medium is poured into iced water and extracted with dichloromethane. The organic phase is dried on an anhydrous sodium sulphate and it is evaporated. In this way, there is obtained the 2-(cyclopropylcarbonyl)-1,3,4,6,7,11b-hexahydro-2H-pyrazino(2,1-a)-4-isoquinoleinone; m.p.=148°-149° C., yield: 57%.

Workup

  1. additionTo the reaction medium is added
  2. customIt is evaporated to dryness under reduced pressure
  3. additionthe residue is taken up in a mixture of water and methylene chloride
  4. dry with materialthe decanted organic phase is dried over dry sodium sulphate
  5. customThe solvent is evaporated
  6. customthe residue, formed by crude 4-(cyclopropylcarbonyl)-2,6-dioxo-1-phenethyl piperazine
  7. customThe solution as thus obtained
  8. additionhas added
  9. customkept at 0° C.
  10. waitthe reaction medium is left for 45 minutes at 0° C
  11. customis destroyed
  12. additionby adding acetone
  13. filtrationThe insoluble salts are filtered
  14. customthe filtrate is evaporated to dryness
  15. additionthe residue is treated with a mixture of water and methylene chloride
  16. dry with materialThe decanted organic phase is dried over dry sodium sulphate
  17. customevaporated to dryness
  18. filtrationThe residue is purified by filtration on a silica bed
  19. customthe product as thus obtained

Sources & evidence

ORD record
ord-0c19776b0ba04f378072594cbcb39f08
Source dataset
uspto-grants-1985_06
Patent number
US04523013

Reaction notes

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