Hydrazine hydrate (1:1) → Hydralazine

HRID 1353056Notes

Reaction equation

HRID 1353056 reaction equation
O.[NH2:2][NH2:3].Cl[C:5]1[C:14]2[C:9](=[CH:10][CH:11]=[CH:12][CH:13]=2)[CH:8]=[N:7][N:6]=1>C(O)C>[CH:11]1[CH:12]=[CH:13][C:14]2[C:9](=[CH:8][N:7]=[N:6][C:5]=2[NH:2][NH2:3])[CH:10]=1

Participants

4

Reactant 2

HCID 24654Hydrazine hydrate (1:1)HCID 1607931-Chlorophthalazine

Product 1

HCID 3637Hydralazine

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

To a 2-L, 3-necked, round-bottom flask fitted with a temperature probe and condenser were charged 700 mL of ethanol and 7.6 mole equivalents (630 mL) of hydrazine hydrate, and the solution was cooled to <10° C. One (1) mole equivalent (280 g) of 1chlorophthalazine (solid) was added in portions at a rate to maintain the solution temperature at <20° C. The solution was stirred and heated to 60–70° C. After 1 hour at temperature, the hot solution was filtered to remove any insoluble by-products, and the filtrate was cooled to 0–5° C. A light yellow solid formed in the cold solution, and was isolated by filtration and washed with cold ethanol. The resulting product, hydralazine free base, was dried to constant mass and characterized. Typical yields were in the range 77–80%. The hydralazine thus obtained could be used in the next step without purification.

Workup

  1. temperaturethe solution was cooled to <10° C
  2. temperatureto maintain the solution temperature at <20° C
  3. temperatureheated to 60–70° C
  4. filtrationthe hot solution was filtered
  5. customto remove any insoluble by-products
  6. temperaturethe filtrate was cooled to 0–5° C
  7. customA light yellow solid formed in the cold solution
  8. customwas isolated by filtration
  9. washwashed with cold ethanol
  10. dry with materialThe resulting product, hydralazine free base, was dried to constant mass
  11. customTypical yields

Sources & evidence

ORD record
ord-a2ed64ef46f44a71bf4c01322e79cdf1
Source dataset
uspto-grants-2007_05
Patent number
US07220858B2

Reaction notes

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