O-Xylene → Phthalazine

HRID 427333

Reaction equation

HRID 427333 reaction equation
O=[N:2][NH2:3].Cl.C(N(CC)CC)C.[C:12]1([CH3:19])[C:13]([CH3:18])=[CH:14][CH:15]=[CH:16][CH:17]=1>>[CH:18]1[C:13]2[C:12](=[CH:17][CH:16]=[CH:15][CH:14]=2)[CH:19]=[N:3][N:2]=1

Participants

4

Reactant 3

HCID 7237O-XyleneHCID 11130Triethylamine hydrochlorideHCID 37183Nitrosamine

Product 1

HCID 9207PhthalazineYield 74%

Procedure

1,1′-Carbonyldiimidazole (0.917 g, 5.65 mmol) was added to a stirred solution of 3-furoic acid (0.634 g, 5.65 mmol) in DMF (30 ml). The solution was stirred for 2 h before adding the preceding hydrazine (1.19 g, 5.14 mmol) and triethylamine (0.71 ml, 5.14 mmol) and triethylamine (0.71 ml, 5.14 mmol). After 18 h at room temperature, the solvent was evaporated in vacuo and water added to the residue. The resultant precipitate was collected by filtration, washed with water and hexane and dried in vacuo to give the ketohydrazine (0.66 g, 45%), MS (ES+) m/e 289 [MH]+. A solution of the ketohydrazine (0.66 g, 2.3 mmol) and triethylamine hydrochloride (0.07 g, 0.5 mmol) in xylene (40 ml) was heated at reflux for 18 h. The solution was cooled to room temperature and the solvent evaporated in vacuo. Diethyl ether was added to the residue and the resulting solid collected by filtration, washed with diethyl ether and dried in vacuo to give the title-phthalazine (0.46 g, 74%), 1H NMR (250 MHz, CDCl3) δ 7.32 (1H, d, J=1.8 Hz, Ar—H), 7.62 (1H, d, J=1.4 Hz. Ar—H), 7.90 (1H, m, Ar—H), 8.04 (1H, t, J=7.6 Hz, Ar—H), 8.31 (1H, d, J=8.2 Hz, Ar—H), 8.58 (1H, s, Ar—H), 8.75 (1H, d, Ar—H); MS (ES+) m/e 271 [MH]+.

Workup

  1. temperatureat reflux for 18 h
  2. customthe solvent evaporated in vacuo
  3. additionDiethyl ether was added to the residue
  4. filtrationthe resulting solid collected by filtration
  5. washwashed with diethyl ether
  6. customdried in vacuo

Sources & evidence

ORD record
ord-27d607ace67b48cb9d7c334f9f666a27
Source dataset
uspto-grants-2001_11
Patent number
US06313125B1

Linked notes

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