p-Toluenesulfonic acid → (-)-(4R,trans)-1-[2-(2,4-dichlorophenyl)-4,5-dimethyl-1,3-dioxolan-2-ylmethyl]-1H-1,2,4-triazole

HRID 971645

Reaction equation

HRID 971645 reaction equation
CC1C=CC(S(O)(=O)=O)=CC=1.[Cl:12][C:13]1[CH:18]=[C:17]([Cl:19])[CH:16]=[CH:15][C:14]=1[C:20](OC)(OC)[CH2:21][N:22]1[CH:26]=[N:25][CH:24]=[N:23]1.[CH3:31][C@@H:32]([OH:36])[C@H:33]([OH:35])[CH3:34].CC1C=CC(S(O)(=O)=O)=CC=1.[OH-].[Na+]>CC1C=CC=CC=1>[Cl:12][C:13]1[CH:18]=[C:17]([Cl:19])[CH:16]=[CH:15][C:14]=1[C:20]1([CH2:21][N:22]2[CH:26]=[N:25][CH:24]=[N:23]2)[O:36][C@H:32]([CH3:31])[C@@H:33]([CH3:34])[O:35]1

Participants

6

Reactant 4

HCID 6101p-Toluenesulfonic acidHCID 14798Sodium HydroxideHCID 225936(2R,3R)-ButanediolHCID 230442891-[2-(2,4-dichlorophenyl)-2,2-dimethoxyethyl]-1H-1,2,4-triazole 4-methylbenzenesulfonate

Product 1

HCID 53665691(-)-(4R,trans)-1-[2-(2,4-dichlorophenyl)-4,5-dimethyl-1,3-dioxolan-2-ylmethyl]-1H-1,2,4-triazoleYield 50%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

A mixture of 9.5 parts of 1-[2(2,4-dichlorophenyl)-2,2-dimethoxyethyl]-1H-1,2,4-triazole 4-methylbenzenesulfonate, 2 parts of (2R, 3R)(-)-2,3-butanediol, 1 part of 4-methylbenzenesulfonic acid and 90 parts of methylbenzene is stirred and refluxed for 3 days. The reaction mixture is cooled and alkalized with a sodium hydroxide solution 20%. The whole is poured onto water and the product is extracted with dichloromethane. The extract is dried, filtered and evaporated. The residue is purified by column-chromatography over silica gel using ethyl acetate as eluent. The pure fractions are collected and the eluent is evaporated. The residue is crystallized from a mixture of 2,2'oxybispropane and petroleumether (1:1 by volume). The product is filtered off and dried, yielding 3.2 parts (50%) of (-)-(4R,trans)-1-[2-(2,4-dichlorophenyl)-4,5-dimethyl-1,3-dioxolan-2-ylmethyl]-1H-1,2,4-triazole; mp. 82.5° C.; [α]D =-30.26° (c=0.5% CHCl3)

Workup

  1. temperaturerefluxed for 3 days
  2. temperatureThe reaction mixture is cooled
  3. additionThe whole is poured onto water
  4. extractionthe product is extracted with dichloromethane
  5. customThe extract is dried
  6. filtrationfiltered
  7. customevaporated
  8. customThe residue is purified by column-chromatography over silica gel
  9. customThe pure fractions are collected
  10. customthe eluent is evaporated
  11. customThe residue is crystallized from a mixture of 2,2'oxybispropane and petroleumether (1:1 by volume)
  12. filtrationThe product is filtered off
  13. customdried

Sources & evidence

ORD record
ord-8418095d445b44b6a8a233742033e674
Source dataset
uspto-grants-1979_07
Patent number
US04160838

Linked notes

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