Triphosgene → 6-chloro-7-(morpholin-4-yl)-2H-1,2,4-triazolo[4,3-b]pyridazin-3-one

HRID 47232Notes

Reaction equation

HRID 47232 reaction equation
Cl[C:2](Cl)([O:4]C(=O)OC(Cl)(Cl)Cl)Cl.[Cl:13][C:14]1[N:19]=[N:18][C:17]([NH:20][NH2:21])=[CH:16][C:15]=1[N:22]1[CH2:27][CH2:26][O:25][CH2:24][CH2:23]1>ClCCCl>[Cl:13][C:14]1[C:15]([N:22]2[CH2:27][CH2:26][O:25][CH2:24][CH2:23]2)=[CH:16][C:17]2[N:18]([C:2](=[O:4])[NH:21][N:20]=2)[N:19]=1

Participants

4

Reactant 2

HCID 94429TriphosgeneHCID 2161086-Chloro-5-(morpholin-4-yl)pyridazin-3-ylhydrazine

Product 1

HCID 227441686-chloro-7-(morpholin-4-yl)-2H-1,2,4-triazolo[4,3-b]pyridazin-3-oneYield 172.1%

Reagents, catalysts & solvents 1

HCID 111,2-DichloroethaneSolvent

Procedure

Triphosgene (750 mg, 2.5 mmol) was added to a stirred solution of 6-chloro-5-(morpholin-4-yl)pyridazin-3-ylhydrazine (1.42 g, 6.2 mmol) in 1,2-dichloroethane (60 ml) at room temperature under nitrogen. The mixture was then stirred and heated at reflux for 22 hours. Upon cooling the precipitate was collected by filtration. The solid was washed with diethyl ether and then dried in vacuo to give 6-chloro-7-(morpholin-4-yl)-2H-1,2,4-triazolo[4,3-b]pyridazin-3-one (1.1 g, 67%) which was used without further purification. Data for the title compound: 1H NMR (250 MHz, d6-DMSO) δ3.02-3.05 (4H, m), 3.72-3.76 (4H, m), 7.19 (1H, s), 12.57 (1H, br s); MS (ES+) m/e 256, 258 [MH+].

Workup

  1. temperatureheated
  2. temperatureat reflux for 22 hours
  3. temperatureUpon cooling the precipitate
  4. filtrationwas collected by filtration
  5. washThe solid was washed with diethyl ether
  6. customdried in vacuo

Sources & evidence

ORD record
ord-9a5030848b034b208688aef850c24c30
Source dataset
uspto-grants-2004_03
Patent number
US06699859B1

Reaction notes

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