Bromazepam → 7-bromo-2,3-dihydro-2-oxo-alpha-propyl-5-(2-pyridyl)-1H-1,4-benzodiazepine-1-acetic acid methyl ester

HRID 1580607Notes

Reaction equation

HRID 1580607 reaction equation
[Br:1][C:2]1[CH:3]=[CH:4][C:5]2[NH:11][C:10](=[O:12])[CH2:9][N:8]=[C:7]([C:13]3[CH:18]=[CH:17][CH:16]=[CH:15][N:14]=3)[C:6]=2[CH:19]=1.C[O-].[Na+].CN(C)C=O.Br[CH:29]([CH2:34][CH2:35][CH3:36])[C:30]([O:32][CH3:33])=[O:31]>O.C1(C)C=CC=CC=1>[CH3:33][O:32][C:30](=[O:31])[CH:29]([CH2:34][CH2:35][CH3:36])[N:11]1[C:5]2[CH:4]=[CH:3][C:2]([Br:1])=[CH:19][C:6]=2[C:7]([C:13]2[CH:18]=[CH:17][CH:16]=[CH:15][N:14]=2)=[N:8][CH2:9][C:10]1=[O:12]

Participants

7

Reactant 4

HCID 2441BromazepamHCID 6228DimethylformamideHCID 529992Methyl 2-bromopentanoateHCID 10942334Sodium Methoxide

Product 1

HCID 543891827-bromo-2,3-dihydro-2-oxo-alpha-propyl-5-(2-pyridyl)-1H-1,4-benzodiazepine-1-acetic acid methyl ester

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 1140TolueneSolvent

Procedure

A mixture of 0.1 mole of 7-bromo-1,3-dihydro-5-(2-pyridyl)-2H-1,4-benzodiazepin-2-one and 0.11 mole of sodium methoxide in about 200 ml. of dimethylformamide is heated at about 95° c. for about 20 minutes. To the mixture is added a solution of 0.11 mole of methyl 2-bromovalerate in about 200 ml. of toluene over a period of about 1 hour at about 95° C., and heating is continued for an additional period of about 6 hours. The reaction mixture is then evaporated in vacuo and the residue thus obtained is stirred with about 500 ml. of water. The resulting suspension is filtered and the solids thus obtained are crystallized from a suitable organic solvent such as ether, methanol, methylene chloride, methylene chloride-methanol and the like to obtain 7-bromo-2,3-dihydro-2-oxo-α-propyl-5-(2-pyridyl)-1H-1,4-benzodiazepine-1-acetic acid methyl ester.

Workup

  1. temperatureheating
  2. waitis continued for an additional period of about 6 hours
  3. customThe reaction mixture is then evaporated in vacuo
  4. customthe residue thus obtained
  5. filtrationThe resulting suspension is filtered
  6. customthe solids thus obtained
  7. customare crystallized from a suitable organic solvent such as ether, methanol, methylene chloride, methylene chloride-methanol

Sources & evidence

ORD record
ord-c162350d230341889fa0982c0460e1bc
Source dataset
uspto-grants-1976_01
Patent number
US03933816

Reaction notes

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