4-(Bromoacetyl)benzonitrile → 2-amino-5-(4-cyano-phenyl)-1H-pyrrole-3-carboxylic acid ethyl ester

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A mixture of 42.53 g (0.255 mol) carbamimidoyl-acetic acid ethyl ester hydrochloride in 70 ml absolute ethanol is treated at 0 to 5° C. with 95.3 ml of a 21% sodium ethoxide solution in ethanol (0.255 mol) and stirred 5 min at 0 to 5° C. 4-Bromoacetyl-benzonitrile (28.6 g, 0.128 mol) is then added in portions over 20 min at 0 to 5° C. Stirring is continued at this temperature for 5 min then the ice bath is removed and the yellow suspension is stirred over night at RT. The solid is filtered off, washed with ethanol and ether and re-suspended in 450 ml actonitrile. The mixture is heated for 5 min under reflux, filtered while still hot and then cooled in an ice bath. The title compound is collected by succion and dried. Flash chromatography (dichtoromethane/ethyl acetate mixture) of the mother liquors gives an additional crop of the title compound as a yellow solid; m.p. 228-229° C.; MS-ES+: (M+H)+=254.

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