Piperazine Dihydrochloride → Irbesartan

HRID 659751

Reaction equation

HRID 659751 reaction equation
[CH2:1]([C:5]1[N:9]([CH2:10][C:11]2[CH:16]=[CH:15][C:14]([C:17]3[CH:22]=[CH:21][CH:20]=[CH:19][C:18]=3[C:23]#[N:24])=[CH:13][CH:12]=2)[C:8](=[O:25])[C:7]2([CH2:29][CH2:28][CH2:27][CH2:26]2)[N:6]=1)[CH2:2][CH2:3][CH3:4].[N-:30]=[N+:31]=[N-:32].[Na+].Cl.Cl.N1CCNCC1.[OH-].[Na+]>CN(C)C=O.O>[CH3:4][CH2:3][CH2:2][CH2:1][C:5]1[N:9]([CH2:10][C:11]2[CH:16]=[CH:15][C:14]([C:17]3[CH:22]=[CH:21][CH:20]=[CH:19][C:18]=3[C:23]3[N:32]=[N:31][NH:30][N:24]=3)=[CH:13][CH:12]=2)[C:8](=[O:25])[C:7]2([CH2:26][CH2:27][CH2:28][CH2:29]2)[N:6]=1

Participants

7

Reactant 4

HCID 8893Piperazine DihydrochlorideHCID 14798Sodium HydroxideHCID 33557Sodium AzideHCID 98431164'-((2-Butyl-4-oxo-1,3-diazaspiro(4.4)non-1-ene-3-yl)methyl)(1,1'-biphenyl)-2-carbonitrile

Product 1

HCID 3749IrbesartanYield 98%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6228DimethylformamideSolvent

Procedure

A mixture of 2-n-butyl-3-[(2′-cyanobiphenyl-4-yl)methyl]-1,3-diazaspiro-[4,4]-non-1-en-4-one (10 g), sodium azide (7.7 g) and piperazine dihydrochloride (7.5 g) in N,N-dimethylformamide (30 ml) was refluxed for 7 hours under stirring. The reaction was cooled to room temperature and 20 ml water was added. The reaction mixture was adjusted to pH of about 12 using 10% NaOH solution. The alkaline solution was washed with toluene (15 ml) and the aqueous phase was neutralized to pH of 6.5 using concentrated HCl. The resulting suspension was stirred for 3 hours at room temperature and filtered to obtain irbesartan (5.8 g, 98% purity by HPLC). Recrystallization of the Product using ethanol results in 5.2 g of irbesartan with 99.94% purity and content of the impurity 2-n-butyl-3-[(2′-carboxamidobiphenyl-4-yl)methyl]-1,3-diazaspiro-[4,4]-non-1-en-4-one: 0.07%.

Workup

  1. temperaturewas refluxed for 7 hours
  2. washThe alkaline solution was washed with toluene (15 ml)
  3. stirringThe resulting suspension was stirred for 3 hours at room temperature
  4. filtrationfiltered

Sources & evidence

ORD record
ord-a87991bb691b4f3d9269906fa7cf021a
Source dataset
uspto-grants-2011_12
Patent number
US08080670B2

Linked notes

Loading…