Hydrochloric Acid → (Oxan-4-yl)hydrazine hydrochloride

HRID 12882

Reaction equation

HRID 12882 reaction equation
C(OC([NH:8][N:9]=[C:10]1[CH2:15][CH2:14][O:13][CH2:12][CH2:11]1)=O)(C)(C)C.C([BH3-])#N.[Na+].[ClH:20]>O1CCCC1.CO>[ClH:20].[O:13]1[CH2:14][CH2:15][CH:10]([NH:9][NH2:8])[CH2:11][CH2:12]1

Participants

6

Reactant 3

HCID 313Hydrochloric AcidHCID 5003444Sodium cyanoborohydrideHCID 67020854tert-Butyl 2-(dihydro-2H-pyran-4(3H)-ylidene)hydrazinecarboxylate

Product 1

HCID 17773358(Oxan-4-yl)hydrazine hydrochlorideYield 60%

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 8028TetrahydrofuranSolvent

Procedure

N′-(Tetrahydro-pyran-4-ylidene)-hydrazinecarboxylic acid tert-butyl ester (5.210 g, 24.32 mmol) was dissolved in a mixture of dry tetrahydrofuran (22 mL) and dry methanol (30 mL). Sodium cyanoborohydride was added to the solution resulting in effervescence. When the effervescence subsided, the mixture was heated to reflux for 5-10 minutes. After cooling to room temperature 6N HCl (10.5 mL) was slowly added and then the mixture was heated to reflux for 20 minutes. After cooling to room temperature, the solvent was removed in vacuo. The residue was triturated with hot isopropanol and then cooled to room temperature, diluted with ether and chilled. The solid was collected by filtration and was found to be the reduced material but not completely deprotected. The solid was dissolved in the same THF-methanol mixture and treated with 6N HCl (10.5 mL) at reflux for another 1.5 hours. After cooling to room temperature, the reaction mixture was filtered to remove a small amount of insoluble material. The filtrate was then concentrated in vacuo. Isopropanol was added to the residue and solid quickly began to crystallize out of solution. After chilling overnight, ether was added followed by additional chilling. The solid was then collected by filtration, washed with ether and dried in vacuo to give (tetrahydro-pyran-4-yl)-hydrazine hydrochloride (2.22 g, 60%).

Workup

  1. customresulting in effervescence
  2. temperaturethe mixture was heated
  3. temperatureto reflux for 5-10 minutes
  4. additionwas slowly added
  5. temperaturethe mixture was heated
  6. temperatureto reflux for 20 minutes
  7. customthe solvent was removed in vacuo
  8. customThe residue was triturated with hot isopropanol
  9. temperaturecooled to room temperature
  10. additiondiluted with ether
  11. temperaturechilled
  12. filtrationThe solid was collected by filtration
  13. dissolutionThe solid was dissolved in the same THF-methanol mixture
  14. additiontreated with 6N HCl (10.5 mL)
  15. temperatureat reflux for another 1.5 hours
  16. temperatureAfter cooling to room temperature
  17. filtrationthe reaction mixture was filtered
  18. customto remove a small amount of insoluble material
  19. concentrationThe filtrate was then concentrated in vacuo
  20. additionIsopropanol was added to the residue and solid
  21. customto crystallize out of solution
  22. temperatureAfter chilling overnight
  23. additionether was added
  24. filtrationThe solid was then collected by filtration
  25. washwashed with ether
  26. customdried in vacuo

Sources & evidence

ORD record
ord-c16e7b37770e484cb17a492d52bea981
Source dataset
uspto-grants-2010_06
Patent number
US07728029B2

Linked notes

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