Sodium Hydroxide → 7-fluoro-6-hydrazino-4-propargyl-2H-1,4-benzoxazin-3-one

HRID 476516Notes

Reaction equation

HRID 476516 reaction equation
[NH2:1][C:2]1[C:3]([F:16])=[CH:4][C:5]2[O:10][CH2:9][C:8](=[O:11])[N:7]([CH2:12][C:13]#[CH:14])[C:6]=2[CH:15]=1.[N:17]([O-])=O.[Na+].[OH-].[Na+]>Cl>[F:16][C:3]1[C:2]([NH:1][NH2:17])=[CH:15][C:6]2[N:7]([CH2:12][C:13]#[CH:14])[C:8](=[O:11])[CH2:9][O:10][C:5]=2[CH:4]=1

Participants

5

Reactant 3

HCID 14798Sodium HydroxideHCID 111603236‐Amino‐7‐fluoro‐4‐(prop‐2‐yn‐1‐yl)‐3,4‐dihydro‐2H‐ 1,4‐benzoxazin‐3‐oneHCID 23668193Sodium Nitrite

Product 1

HCID 145179487-fluoro-6-hydrazino-4-propargyl-2H-1,4-benzoxazin-3-oneYield 59.1%

Reagents, catalysts & solvents 1

HCID 313Hydrochloric AcidSolvent2×

Procedure

A suspension of 6-amino-7-fluoro-4-propargyl-2H-1,4-benzoxazin-3(4H)-one (13.0 g) in conc. hydrochloric acid (70 g) was cooled to 0° to 5° C., and a saturated solution of sodium nitrite (5.1 g) was dropwise added thereto at 0° to 5° C., followed by stirring for 2 hours. The resultant mixture was cooled to -30° C., and a solution of anhydrous stannous chloride (28.1 g) in conc. hydrochloric acid (30 g) was added thereto at once, followed by stirring at 0° to 5° C. for 3 hours. Celite (50 g) was added to the reaction mixture, which was neutralized with 10% aqueous sodium hydroxide solution below 10° C. The resulting mixture was filtered, and the filtrate was extracted with ethyl acetate. The extract was washed with water, dried and concentrated to give 7-fluoro-4-propargyl-2H-1,4-benzoxazin-3(4H)-on-6-ylhydrazine (8.2 g).

Workup

  1. temperaturewas cooled to 0° to 5° C.
  2. customat 0° to 5° C.
  3. stirringby stirring at 0° to 5° C. for 3 hours
  4. additionCelite (50 g) was added to the reaction mixture, which
  5. filtrationThe resulting mixture was filtered
  6. extractionthe filtrate was extracted with ethyl acetate
  7. washThe extract was washed with water
  8. customdried
  9. concentrationconcentrated

Sources & evidence

ORD record
ord-49d2c13cfde4445397870def5edc38ae
Source dataset
uspto-grants-1989_12
Patent number
US04885024

Reaction notes

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