Water → t-butyl 5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate

HRID 223194Notes

Reaction equation

HRID 223194 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]([OH:19])=[O:18])=[C:4]2[CH2:3]1.[C:20](O)([CH3:23])([CH3:22])[CH3:21].P(Cl)(Cl)(Cl)=O.O>N1C=CC=CC=1>[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]([O:19][C:20]([CH3:23])([CH3:22])[CH3:21])=[O:18])=[C:4]2[CH2:3]1

Participants

6

Reactant 4

HCID 962WaterHCID 6386tert-ButanolHCID 24813Phosphorus oxychlorideHCID 103326765-methyl-6-oxo-5,6-dihydro-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylic acid

Product 1

HCID 398203t-butyl 5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate

Reagents, catalysts & solvents 1

HCID 1049PyridineSolvent

Procedure

A suspension of 2.6 g (10 mmol) of 5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylic acid in 20 ml of pyridine is firstly treated with 25 ml of t-butanol and subsequently treated dropwise at -5° with 1.1 ml of phosphorus oxychloride. The mixture is stirred at -5° for 15 minutes and at room temperature for 48 hours, poured into 250 ml of water and extracted four times with chloroform. The chloroform extracts are washed three times with dilute sodium hydroxide and three times with water, dried over magnesium sulphate and evaporated. After recrystallization of the residue from ethyl acetate, there is obtained t-butyl 5,6-dihydro-5-methyl-6-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylate of melting point 216°-217°.

Workup

  1. extractionextracted four times with chloroform
  2. washThe chloroform extracts are washed three times with dilute sodium hydroxide and three times with water
  3. dry with materialdried over magnesium sulphate
  4. customevaporated
  5. customAfter recrystallization of the residue from ethyl acetate

Sources & evidence

ORD record
ord-2f74af6265f048dfabc3320eefd0a0c7
Source dataset
uspto-grants-1982_10
Patent number
US04352817

Reaction notes

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