Trifluoroacetic acid → N-[6-(3-chloro-thiophene-2-carbonyl)-5,6,7,8-tetrahydro-pyrido[4,3-d]pyrimidin-2-yl]-2-ethoxy-benzamide

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Trifluoroacetic acid 3.6 ml (49 mmol) was added to a solution of 2-(2-ethoxy-benzoylamino)-7,8-dihydro-5H-pyrido[4,3-d]pyrimidine-6-carboxylic acid tert-butyl ester 300 mg (0.753 mmol) in CH2Cl2 (10 ml) under nitrogen as inert gas and stirring was performed for 2 h at RT. After removal of the solvent, the intermediate (2-ethoxy-N-(5,6,7,8-tetrahydro-pyrido[4,3-d]pyrimidin-2-yl)-benzamide trifluoroacetate) was dissolved in CH2Cl2 (10 ml) and DIPEA 225 μl and 3-chlorothiophene-2-carboxylic acid 129 mg (0.791 mmol) were added. After cooling the reaction mixture to 0° C., EDCI 158 mg (0.828 mmol) and HOAt 15 mg (0.11 mmol) were added. The reaction mixture was stirred for 1 h at 0° C. and then overnight at RT. After removal of the solvent, purification was performed by means of column chromatography and the product N-[6-(3-chloro-thiophene-2-carbonyl)-5,6,7,8-tetrahydro-pyrido[4,3-d]pyrimidin-2-yl]-2-ethoxy-benzamide 170 mg (0.38 mmol, 51% of theoretical) was obtained.

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