Aniline → HCID 54043359, compound

Participants

Reaction Steps

A solution of 1.31 g (3 mmol) 4,5-Bis(trimethylsilyloxy)-cyclohexa-1,4-diene-1,2-dicarboxylic acid dimethyl ester (Example 1a), 306 mg (3 mmol) pivalic acid and 1 ml of DMF is heated under argon to 120° and a solution of 460 mg (3 mmol) 2,4-dimethoxy-anilin in 1 ml of DMF is added within 5 minutes. The reaction mixture is heated at 120° for 10 minutes, cooled, diluted with water and extracted with ethyl acetate. The organic phase is washed in succession with 1N HCl, water, saturated Na2CO3, water and brine, dried with magnesium sulfate and concentrated by evaporation. The evaporation residue, a brown oil, 402 mg (3.9 mmol) pivalic acid and 2 ml of ethanol are heated to reflux and a solution of 358 μl (3.9 mmol) of aniline in 3 ml of ethanol is added dropwise. The reaction mixture is heated to reflux for 15 hours, cooled, diluted with water and extracted with ethyl acetate. The organic phase is washed in succession with 1N HCl,water, saturated Na2CO3, water and brine, dried with magnesium sulfate and concentrated by evaporation. The evaporation residue is chromatographed on silica gel with ethyl acetate/hexane 1:2 and the product fractions are concentrated by evaporation. This way, in the first product fractions 4-anilino-5-(2,4-dimethoxy-anilino)-phthalic acid dimethyl ester is obtained in the form of a yellow oil: FAB-MS: 437 [M+ +H]. The evaporation residue of the product fractions following thereafter is recrystallized, and 4,5-bis-(2,4-dimethoxy-anilino)-phthalicacid dimethyl ester is obtained in the form of a yellow foam: FAB-MS: 497 [M+ +H].

Provenance & Evidence