Ethyl orthoformate → 4-chloro-7-isopropyl-7H-imidazo[4,5-c]pyridazine

Reaction equation

[Cl:1][C:2]1[C:3]([NH2:12])=[C:4]([NH:8][CH:9]([CH3:11])[CH3:10])[N:5]=[N:6][CH:7]=1.[CH:13](OCC)(OCC)OCC>>[Cl:1][C:2]1[C:3]2[N:12]=[CH:13][N:8]([CH:9]([CH3:10])[CH3:11])[C:4]=2[N:5]=[N:6][CH:7]=1

Participants

Reactant 2

HCID 31214Ethyl orthoformate

HCID 867232295-Chloro-N3-isopropylpyridazine-3,4-diamine

Product 1

HCID 867232144-chloro-7-isopropyl-7H-imidazo[4,5-c]pyridazineYield 76%

Conditions

Temperature: 130 °C

Procedure

A mixture of 5-chloro-N3-isopropylpyridazine-3,4-diamine (Preparation 5, 1020 mg, 5.47 mmol) in triethyl orthoformate (9 mL) was heated at 130° C. for 80 minutes. The solvent was removed in vacuo and the residue dissolved in MeOH/DCM and purified by silica gel column chromatography eluting with EtOAc:heptane 0-63% to provide the titled product as a white solid in 76% yield, 816 mg.

Workup

customThe solvent was removed in vacuo
dissolutionthe residue dissolved in MeOH/DCM
custompurified by silica gel column chromatography
washeluting with EtOAc

Sources & evidence

ORD record: ord-dc5413d2e1f44c3e92c4617ca3958038
Source dataset: uspto-grants-2015_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08952008B2

Reaction notes

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