Hydrazine hydrate (1:1) → 4-(3-amino-4-chlorobenzyl)-2H-phthalazin-1-one

HRID 459777Notes

Reaction equation

HRID 459777 reaction equation
[NH2:1][C:2]1[CH:3]=[C:4]([CH:16]=[CH:17][C:18]=1[Cl:19])[CH:5]=[C:6]1[C:14]2[C:9](=[CH:10][CH:11]=[CH:12][CH:13]=2)[C:8](=O)[O:7]1.O.[NH2:21][NH2:22]>>[NH2:1][C:2]1[CH:3]=[C:4]([CH:16]=[CH:17][C:18]=1[Cl:19])[CH2:5][C:6]1[C:14]2[C:9](=[CH:10][CH:11]=[CH:12][CH:13]=2)[C:8](=[O:7])[NH:22][N:21]=1

Participants

3

Reactant 2

HCID 24654Hydrazine hydrate (1:1)HCID 686232423-(3-amino-4-chlorobenzylidene)-3H-isobenzofuran-1-one

Product 1

HCID 184443724-(3-amino-4-chlorobenzyl)-2H-phthalazin-1-oneYield 70.8%

Procedure

A stirred mixture of the above 3-(3-amino-4-chlorobenzylidene)-3H-isobenzofuran-1-one (0.815 g, 3 mmol), industrial methylated spirit (10 ml) and hydrazine monohydrate (0.15 g, 3 mmol) was heated under reflux for 1 hour then cooled to ambient temperature. The resulting solid was collected by filtration, washed with industrial methylated spirit (5 ml) and water (5 ml), and dried in vacuo to give a pale grey solid. The crude material was recrystallised from acetonitrile (140 ml) and the resulting solid was collected by filtration and dried in vacuo to give 4-(3-amino-4-chlorobenzyl)-2H-phthalazin-1-one (0.607 g) as an off-white solid, m.pt. 227–228° C.; 250 MHz 1H-nmr (d6-DMSO) δ (ppm): 4.05 (s, 2H) (ArCH2—), 5.2 (s, 2H) (—NH2), 6.4–6.5 (m, 1H) (ArH), 6.6–6.7 (m, 1H) (ArH), 6.95–7.05 (m, 1H) (ArH), 7.65–7.85 (m, 3H) (3×ArH), 8.1–8.2 (m, 1H) (ArH), 12.5 (s, 1H) (CONH) ; m/z (M+H)+. 286/288, 100% purity.

Workup

  1. temperaturewas heated
  2. temperatureunder reflux for 1 hour
  3. filtrationThe resulting solid was collected by filtration
  4. washwashed with industrial methylated spirit (5 ml) and water (5 ml)
  5. customdried in vacuo
  6. customto give a pale grey solid
  7. customThe crude material was recrystallised from acetonitrile (140 ml)
  8. filtrationthe resulting solid was collected by filtration
  9. customdried in vacuo

Sources & evidence

ORD record
ord-1747537cef464ad791494fe346b2fbb6
Source dataset
uspto-grants-2007_03
Patent number
US07196085B2

Reaction notes

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