3-(Trifluoromethyl)phenyl isocyanate → HCID 11438779, compound

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Reaction Steps

3-Aminopyrazine-2-carboxylic acid (0.7 g) in DMSO (10 ml) was treated with 3-trifluoromethylphenylisocyanate (0.9 ml), stirred at room temperature overnight and then quenched with water. A gummy residue separated. After decantation the residue was washed thoroughly with water, stirred with NaOH to basic pH, filtered and chromatographied on silica with CH2Cl2:MeOH:acetone (4:1:1) followed by CH2Cl2:MeOH:NH4OH (40:9:1) when the product started coming off the column. This gave 3-[3-(3-trifluoromethyl-phenyl)-ureido]-pyrazine-2-carboxylic acid. Mp.>300° C.

Provenance & Evidence