Hydrochloric Acid → 1-[(3,5-Difluoro-4-methoxyphenyl)methyl]-1,3-dihydro-2H-imidazole-2-thione

HRID 1252493Notes

Reaction equation

HRID 1252493 reaction equation
[CH3:1][O:2][C:3]1[C:10]([F:11])=[CH:9][C:6]([CH:7]=O)=[CH:5][C:4]=1[F:12].CO[CH:15](OC)[CH2:16][NH2:17].Cl.[S-:21][C:22]#[N:23].[K+]>C(O)C.[Pd].CO>[CH3:1][O:2][C:3]1[C:10]([F:11])=[CH:9][C:6]([CH2:7][N:17]2[CH:16]=[CH:15][NH:23][C:22]2=[S:21])=[CH:5][C:4]=1[F:12]

Participants

8

Reactant 4

HCID 313Hydrochloric AcidHCID 89728Aminoacetaldehyde dimethyl acetalHCID 516872Potassium thiocyanateHCID 144508603,5-Difluoro-4-methoxybenzaldehyde

Product 1

HCID 144508631-[(3,5-Difluoro-4-methoxyphenyl)methyl]-1,3-dihydro-2H-imidazole-2-thioneYield 72%

Reagents, catalysts & solvents 3

HCID 23938PalladiumCatalystHCID 702EthanolSolventHCID 887MethanolSolvent

Conditions

Temperature
95 °C

Procedure

A mixture of 4-methoxy-3,5-difluorobenzaldehyde (17.2 g, 0.1 mol), aminoacetaldehyde dimethyl acetal (10.5 g, 0.1 mol), and methanol (1 ml) was heated at 95° C. for 10 minutes. The resulting mixture was dissolved in ethanol (150 ml) and hydrogenated over 10% Pd on carbon (1 g) until H2 uptake slowed (about 2 hours). The catalyst was filtered and the filtrate was treated with 1.5N hydrochloric acid (80 ml) and potassium thiocyanate (10.4 g, 0.11 mol). The resulting mixture was boiled until the volume was reduced to 100 ml, then it was heated a reflux an additional 1 hour and cooled to 5° C. The crystalline precipitate was filtered, washed with water, and dried. Recrystallization from ethanol gave 1-(4'-methoxy-3',5'-difluorobenzyl)-1,3-dihydro-2H-imidazole-2-thione, 72% yield, m.p. 156°-158° C.

Workup

  1. custom(about 2 hours)
  2. filtrationThe catalyst was filtered
  3. temperatureit was heated
  4. temperaturea reflux an additional 1 hour
  5. temperaturecooled to 5° C
  6. filtrationThe crystalline precipitate was filtered
  7. washwashed with water
  8. customdried
  9. customRecrystallization from ethanol

Sources & evidence

ORD record
ord-5b761976ebd3462184d616dc27912135
Source dataset
uspto-grants-1988_05
Patent number
US04743613

Reaction notes

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