Nitrite → 5-Cyano-4,5-dihydro-3H-pyrazole-3,4-dicarboxylic acid diethyl ester

HRID 329776Notes

Reaction equation

Cl.[NH2:2][CH2:3][C:4]#[N:5].[C:6]([O:15][CH2:16][CH3:17])(=[O:14])/[CH:7]=[CH:8]/[C:9]([O:11][CH2:12][CH3:13])=[O:10].[N:18]([O-])=O.[Na+].N([O-])=O>C(OCC)(=O)C.O>[CH2:16]([O:15][C:6]([CH:7]1[CH:8]([C:9]([O:11][CH2:12][CH3:13])=[O:10])[CH:4]([C:3]#[N:2])[N:5]=[N:18]1)=[O:14])[CH3:17]

Participants

Conditions

Temperature: 24 °C

Procedure

To a one liter round bottom flask containing a cold (0° C.) slurry of 67.6 g (0.6756 mol) of aminoacetonitrile hydrochloride and 44.2 ml (0.2702 mol) of diethyl fumarate in 300 ml of ethyl acetate, were added dropwise, over one hour, an aqueous solution of 46.6 g (0.6756 mol) of sodium nitrite dissolved in 90 ml of water. The temperature of the reaction mixture was maintained at about 0° C. during the nitrite addition, then warmed to room temperature (24° C.) where the mixture was stirred for about 3 hours. The organic layer was separated from the aqueous layer and then stirred at room temperature overnight to provide a solution of 5-cyano-4,5-dihydro-3H-pyrazole-3,4-dicarboxylic acid diethyl ester dissolved in ethyl acetate.

Workup

additionwere added dropwise, over one hour
customThe organic layer was separated from the aqueous layer
stirringstirred at room temperature overnight

Sources & evidence

ORD record: ord-63a30eece6694620beea1f91faa4e8a3
Source dataset: uspto-grants-1990_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04892956

Reaction notes

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