Emedastine → 1-ethoxycarbonyl-4-(1-(2-ethoxyethyl)-1H-benzimidazol-2-yl)[1,4]diazepane

HRID 1584427

Reaction equation

HRID 1584427 reaction equation
C[N:2]1[CH2:8][CH2:7][CH2:6][N:5]([C:9]2[N:13]([CH2:14][CH2:15][O:16][CH2:17][CH3:18])[C:12]3[CH:19]=[CH:20][CH:21]=[CH:22][C:11]=3[N:10]=2)[CH2:4][CH2:3]1.Cl[C:24]([O:26][CH2:27][CH3:28])=[O:25]>C1(C)C=CC=CC=1.C(OCC)(=O)C>[CH2:27]([O:26][C:24]([N:2]1[CH2:8][CH2:7][CH2:6][N:5]([C:9]2[N:13]([CH2:14][CH2:15][O:16][CH2:17][CH3:18])[C:12]3[CH:19]=[CH:20][CH:21]=[CH:22][C:11]=3[N:10]=2)[CH2:4][CH2:3]1)=[O:25])[CH3:28]

Participants

5

Reactant 2

HCID 3219EmedastineHCID 10928Ethyl chloroformate

Product 1

HCID 143561191-ethoxycarbonyl-4-(1-(2-ethoxyethyl)-1H-benzimidazol-2-yl)[1,4]diazepane

Reagents, catalysts & solvents 2

HCID 1140TolueneSolventHCID 8857Ethyl AcetateSolvent

Conditions

Temperature
80 °C

Procedure

Combine 1-methyl-4-(1-(2-ethoxyethyl)-1H-benzimidazol-2-yl)[1,4]diazepane (1.79 g, 5.9 mmol) and ethyl chloroformate (0.75 mL, 7.8 mmol) in toluene (20 mL). Heat to 80° C. After 2 hours, cool the reaction mixture and dilute with ethyl acetate. Extract with a saturated aqueous sodium bicarbonate solution, dry the organic layer over MgSO4, filter, and evaporate in vacuo to give 1-ethoxycarbonyl-4-(1-(2-ethoxyethyl)-1H-benzimidazol-2-yl)[1,4]diazepane: Rf =0.87 (silica gel, dichloromethane/methanol, 90/10). Combine 1-ethoxycarbonyl-4-(1-(2-ethoxyethyl)-1H-benzimidazol-2-yl)[1,4]diazepane (17.2 g, 47.6 mmol), hydrazine hydrate (40 mL), and potassium hydroxide (40.7 g, 725 mmol) in ethylene glycol (150 mL). Heat to reflux. After 5 hours, cool the reaction mixture and dilute with water (500 mL). Extract three times with dichloromethane. Combine the dichloromethane layers and extract with a saturated aqueous sodium bicarbonate solution and then brine. Dry the organic layer over MgSO4, filter, and evaporate in vacuo to give the title compound: Rf =0.25 (silica gel, dichloromethane/methanol, 90/10).

Workup

  1. temperaturecool the reaction mixture
  2. extractionExtract with a saturated aqueous sodium bicarbonate solution
  3. dry with materialdry the organic layer over MgSO4
  4. filtrationfilter
  5. customevaporate in vacuo

Sources & evidence

ORD record
ord-131926130f2a4137973af6d85c1b175c
Source dataset
uspto-grants-1999_08
Patent number
US05932571

Linked notes

Loading…