Hydrochloric Acid → 3,5-Diphenyl-5-methyldithiohydantoin

HRID 850707Notes

Reaction equation

HRID 850707 reaction equation
CC(C)([O-])C.[K+].[CH3:7][CH:8]([N:15]=[C:16]=[S:17])[C:9]1[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=1.[C:18]1([N:24]=[C:25]=[S:26])[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1.Cl>O1CCCC1.O>[C:18]1([N:24]2[C:25](=[S:26])[C:8]([C:9]3[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=3)([CH3:7])[NH:15][C:16]2=[S:17])[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 7673Phenyl IsothiocyanateHCID 20559(1-Isothiocyanatoethyl)benzeneHCID 23665647Potassium tert-butoxide

Product 1

HCID 148926573,5-Diphenyl-5-methyldithiohydantoinYield 58%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
-70 °C

Procedure

15.1 g (122 mmol) of potassium tert-butoxide are dissolved in 200 ml of tetrahydrofuran in a 500 ml, three-necked, round-bottomed flask under a dry argon atmosphere. The solution is cooled to -70° C. A solution containing 20 g (122 mmol) of alpha-methylbenzyl isothiocyanate, 16.55 g (122 mmol) of phenyl isothiocyanate and 50 ml of tetrahydrofuran is run in dropwise while keeping the temperature of the mixture below -60° C. On completion of addition, the mixture is held for 0.5 hour at -70° C. and then is left to return to room temperature. The mixture is poured into 500 ml of water. The mixture is acidified to pH=1 by addition of N hydrochloric acid. The product is extracted with ethyl acetate (2 extractions, each with 150 ml of solvent). The solution is dried over magnesium sulfate. The solution is concentrated under reduced pressure. The product is crystallized from 50 ml of ether. The precipitate is filtered. 21 g (yield: 58%) of 3,5-diphenyl-5-methyldithiohydantoin are thus obtained as a yellow powder melting at 157° C.

Workup

  1. customthe temperature of the mixture below -60° C
  2. additionOn completion of addition
  3. waitis left
  4. customto return to room temperature
  5. extractionThe product is extracted with ethyl acetate (
  6. extraction2 extractions
  7. dry with materialThe solution is dried over magnesium sulfate
  8. concentrationThe solution is concentrated under reduced pressure
  9. customThe product is crystallized from 50 ml of ether
  10. filtrationThe precipitate is filtered

Sources & evidence

ORD record
ord-76a1c4a5a08046a2b762c20f745eb96d
Source dataset
uspto-grants-2000_01
Patent number
US06018052

Reaction notes

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