2-(6-(Bis(carboxymethyl)amino)-5-(2-(2-(bis(carboxymethyl)amino)-5-methylphenoxy)ethoxy)-2-benzofuranyl)-5-oxazolecarboxylic acid → Bapta

Participants

Reaction Steps

Synthesis of a BAPTA tetramethyl ester that contains a phenolic reactive group (Compound XXV). A hydroxy derivative of BAPTA (4-hydroxy-BAPTA) is synthesized by hydrogenation of one of the key intermediate in the synthesis of the Ca2+ indicator fura-2 [U.S. Pat. No. 4,603,209]. For instance 9.8 g of 4-benzyloxy-5'-methyl BAPTA tetramethyl ester is hydrogenated in 50 mL glacial acetic acid in the presence of 0.3 g 10% palladium on charcoal at 40 psi hydrogen pressure for four hours. The reaction is filtered through a pad of Celite to remove the catalyst and the yellow filtrate is evaporated under reduced pressure to give a light brown oil. This is triturated with 50 mL methanol to yield 7.2 g of 4-hydroxy BAPTA tetramethyl ester as a colorless solid (Compound XXV).

Provenance & Evidence