Acetic Acid → Diethyl 1-(3,4-dimethoxyphenyl)hydrazine-1,2-dicarboxylate

HRID 1607316Notes

Reaction equation

[CH3:1][O:2][C:3]1[CH:4]=[C:5]([Mg]Br)[CH:6]=[CH:7][C:8]=1[O:9][CH3:10].[N:13]([C:20]([O:22][CH2:23][CH3:24])=[O:21])=[N:14][C:15]([O:17][CH2:18][CH3:19])=[O:16].C(O)(=O)C.O>O1CCCC1>[CH2:18]([O:17][C:15]([N:14]([C:5]1[CH:6]=[CH:7][C:8]([O:9][CH3:10])=[C:3]([O:2][CH3:1])[CH:4]=1)[NH:13][C:20]([O:22][CH2:23][CH3:24])=[O:21])=[O:16])[CH3:19]

Participants

Conditions

Temperature: 0 °C

Procedure

A solution of 3,4-dimethoxyphenylmagnesium bromide (prepared from 10.85 g, 50 mmol of 3,4-dimethoxybromobenzene and 1.34 g, 55 mmol magnesium) in 200 ml tetrahydrofuran (hereinafter THF) was cooled to -75° C. and added to a solution of diethyl azodicarboxylate (8.71 g, 50 mmol) in 250 ml THF at -75° C. under an inert atmosphere. The solution was allowed to warm to 0° C. and acetic acid (3 g, 50 mmol) and H2O (20 ml) were added. The organic solution was dried over MgSO4, filtered and evaporated, providing N,N'-bis(ethoxycarbonyl)-3,4-dimethoxyphenylhydrazine as a red oil (15 g, 96% yield). This material was dissolved in isopropanol (500 ml) and 15 g potassium hydroxide was added. The mixture was refluxed under nitrogen for four hours, cooled, and neutralized with acetic acid (15 ml). The mixture was evaporated, the residue was treated with ether and aqueous sodium hydroxide, and the ether solution was dried over MgSO4, filtered and distilled in vacuo. Veratrole was distilled from the mixture, followed by 3,4-dimethoxyphenylhydrazine, which was crystallized from carbon tetrachloride to provide 1.0 g off-white powder, mp 103°-106° C. (dec).

Workup

dry with materialThe organic solution was dried over MgSO4
filtrationfiltered
customevaporated

Sources & evidence

ORD record: ord-27305f6c581e44c5ba92bf512946db50
Source dataset: uspto-grants-1989_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04864032

Reaction notes

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