Potassium Iodide → Astemizole

HRID 1856560

Reaction equation

HRID 1856560 reaction equation
CS(O[CH2:6][CH2:7][C:8]1[CH:13]=[CH:12][C:11]([O:14][CH3:15])=[CH:10][CH:9]=1)(=O)=O.Br.Br.[F:18][C:19]1[CH:24]=[CH:23][C:22]([CH2:25][N:26]2[C:30]3[CH:31]=[CH:32][CH:33]=[CH:34][C:29]=3[N:28]=[C:27]2[NH:35][CH:36]2[CH2:41][CH2:40][NH:39][CH2:38][CH2:37]2)=[CH:21][CH:20]=1.C(=O)([O-])[O-].[Na+].[Na+].[I-].[K+]>CN(C)C=O>[F:18][C:19]1[CH:24]=[CH:23][C:22]([CH2:25][N:26]2[C:30]3[CH:31]=[CH:32][CH:33]=[CH:34][C:29]=3[N:28]=[C:27]2[NH:35][CH:36]2[CH2:37][CH2:38][N:39]([CH2:6][CH2:7][C:8]3[CH:13]=[CH:12][C:11]([O:14][CH3:15])=[CH:10][CH:9]=3)[CH2:40][CH2:41]2)=[CH:21][CH:20]=1

Participants

6

Reactant 4

HCID 4875Potassium IodideHCID 10340Sodium CarbonateHCID 2779772-(4-Methoxyphenyl)ethyl methanesulfonateHCID 3018631Norastemizole hydrobromide

Product 1

HCID 2247AstemizoleYield 48%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
70 °C

Procedure

A mixture of 2.3 parts of 2-(4-methoxyphenyl)ethyl methanesulfonate, 4.9 parts of 1-[(4-fluorophenyl)methyl]-N-(4-piperidinyl)-1H-benzimidazol-2-amine dihydrobromide, 3.2 parts of sodium carbonate, 0.1 parts of potassium iodide and 90 parts of N,N-dimethylformamide is stirred overnight at 70° C. The reaction mixture is poured onto water. The product is extracted with methylbenzene. The extract is washed with water, dried, filtered and evaporated. The residue is purified by column-chromatography over silica gel using a mixture of trichloromethane and methanol (98:2 by volume) as eluent. The pure fractions are collected and the eluent is evaporated. The residue is crystallized from 2,2'-oxybispropane, yielding 2.2 parts (48%) of 1-(4-fluorophenylmethyl)-N-{1-[2-(4-methoxyphenyl)ethyl]-4-piperidinyl}-1H-benzimidazol-2-amine; mp. 172.9° C.

Workup

  1. additionThe reaction mixture is poured onto water
  2. extractionThe product is extracted with methylbenzene
  3. washThe extract is washed with water
  4. customdried
  5. filtrationfiltered
  6. customevaporated
  7. customThe residue is purified by column-chromatography over silica gel using
  8. additiona mixture of trichloromethane and methanol (98:2 by volume) as eluent
  9. customThe pure fractions are collected
  10. customthe eluent is evaporated
  11. customThe residue is crystallized from 2,2'-oxybispropane

Sources & evidence

ORD record
ord-979daa0708dc452abb8295cefc7b72c8
Source dataset
uspto-grants-1980_08
Patent number
US04219559

Linked notes

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