Hydrochloric Acid → 4,5-dihydro-3-(hydroxymethyl)-5-methyl-6H-imidazo[1,5-a][1,4]benzodiazepin-6-one

HRID 223217Notes

Reaction equation

HRID 223217 reaction equation
[CH3:1][N:2]1[C:8](=[O:9])[C:7]2[CH:10]=[CH:11][CH:12]=[CH:13][C:6]=2[N:5]2[CH:14]=[N:15][C:16]([C:17](OCC)=[O:18])=[C:4]2[CH2:3]1.[BH4-].[Li+].Cl>O1CCCC1>[OH:18][CH2:17][C:16]1[N:15]=[CH:14][N:5]2[C:6]3[CH:13]=[CH:12][CH:11]=[CH:10][C:7]=3[C:8](=[O:9])[N:2]([CH3:1])[CH2:3][C:4]=12

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 127597Ro 14-7437HCID 4148881Lithium borohydride

Product 1

HCID 198516024,5-dihydro-3-(hydroxymethyl)-5-methyl-6H-imidazo[1,5-a][1,4]benzodiazepin-6-one

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

21.5 g (75.4 mmol) of ethyl 5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate are dissolved in 250 ml of hot absolute tetrahydrofuran (filtered over Alox basic I) under an argon atmosphere while stirring, cooled to about 30° and treated dropwise with a solution of 1.66 g (75.4 mmol) of lithium borohydride. The mixture is heated to boiling under reflux for 6 hours, cooled to room temperature and treated with 50 ml of 3 N aqueous hydrochloric acid. The mixture is stirred at 60° for a further 2 hours and the tetrahydrofuran is removed in vacuo. The residue is made alkaline with concentrated ammonia and left to stand in an ice-bath for 2 hours. The crude product is filtered off under suction, washed with a large amount of water and recrystallized from ethanol. There is obtained 4,5-dihydro-3-(hydroxymethyl)-5-methyl-6H-imidazo[1,5-a][1,4]benzodiazepin-6-one of melting point 224°-226°.

Workup

  1. temperaturecooled to about 30°
  2. temperatureThe mixture is heated
  3. temperatureunder reflux for 6 hours
  4. stirringThe mixture is stirred at 60° for a further 2 hours
  5. customthe tetrahydrofuran is removed in vacuo
  6. waitleft
  7. filtrationThe crude product is filtered off under suction
  8. washwashed with a large amount of water
  9. customrecrystallized from ethanol

Sources & evidence

ORD record
ord-cfb8399790054035a2aea29b9efad85f
Source dataset
uspto-grants-1982_10
Patent number
US04352818

Reaction notes

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