Hydrochloric Acid → 1,9b-dihydro-3-isopropyl-3-methyl-5H-imidazo[2,1-a]isoindole2(3H),5-dione

HRID 372351Notes

Reaction equation

HRID 372351 reaction equation
[BH4-].[Na+].[CH:3]([C:6]1([CH3:20])[N:10]2[C:11](=[O:18])[C:12]3[C:17]([C:9]2=[N:8][C:7]1=[O:19])=[CH:16][CH:15]=[CH:14][CH:13]=3)([CH3:5])[CH3:4].Cl>C(O)C.O1CCCC1>[CH:3]([C:6]1([CH3:20])[N:10]2[C:11](=[O:18])[C:12]3[C:17]([CH:9]2[NH:8][C:7]1=[O:19])=[CH:16][CH:15]=[CH:14][CH:13]=3)([CH3:5])[CH3:4]

Participants

6

Reactant 3

HCID 313Hydrochloric AcidHCID 27292473-isopropyl-3-methyl-3H-imidazo[2,1-a]isoindole-2,5-dioneHCID 4311764Sodium borohydride

Product 1

HCID 706213931,9b-dihydro-3-isopropyl-3-methyl-5H-imidazo[2,1-a]isoindole2(3H),5-dioneYield 88.7%

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 8028TetrahydrofuranSolvent

Procedure

To a stirred suspension of 10.4 g (0.274 mole) sodium borohydride in 164 ml absolute ethanol under nitrogen was added dropwise at 5° C a solution of 133.9 g (0.548 mole) of 2,5-dihydro-3-isopropyl-3-methyl-3H-imidazo[2,1-a]isoindole-2,5-dione in 155 ml tetrahydrofuran. After the addition, the mixture is stirred a further 3 hours at room temperature and then poured over 1070 g ice with stirring. The mixture is acidified with concentrated HCl and after stirring for 1.5 hours, the precipitate removed by filtration, washed with water and air-dried to give 118.7 g of 1,9b-dihydro-3-isopropyl-3-methyl-5H-imidazo[2,1-a]isoindole-2(3H),5-dione, melting point 178°-200° C.

Workup

  1. additionAfter the addition
  2. stirringwith stirring
  3. stirringafter stirring for 1.5 hours
  4. customthe precipitate removed by filtration
  5. washwashed with water
  6. customair-dried

Sources & evidence

ORD record
ord-4bdf6af040aa4ff7893c7c87d5a480cd
Source dataset
uspto-grants-1978_05
Patent number
US04090860

Reaction notes

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