4-Aminobenzoic Acid → HCID 11227079, compound

Participants

Reaction Steps

A total of 52.8 g (0.12 mole) of 1-ethyl-(E,E)-2,6-bis[2-[4-(pyrrolidinyl)phenyl]ethenyl]pyridinium chloride and 18.6 grams (0.12 mole) of the sodium salt of 4-aminobenzoic acid (sodium salt of p-aminobenzoic acid, Na+ PABA−) were dissolved in 1.3 liters of methanol and this mixture was allowed to stir at room temperature for 4 days during which time a precipitate formed. The reaction mixture was then filtered and the solid salt was air dried and vacuum dried to yield a first crop of 28.0 grams of 1-ethyl-(E,E)-2,6-bis[2-[4-(pyrrolidinyl)phenyl]ethenyl]pyridinium 4-aminobenzoate salt (also termed the PABA salt). The filtrate was concentrated under vacuum to produce more precipitate. Isolation of the second crop was effected by filtration followed by air drying and vacuum drying of the solid to afford a second crop of 42.6 grams of 1-ethyl-(E,E)-2,6-bis[2-[4-(pyrrolidinyl)phenyl]ethenyl]pyridinium 4-aminobenzoate salt (also termed the PABA salt)—high performance liquid chromatography area per cent (HPLC A %) first crop=99.6% excluding PABA; HPLC A % second crop=99.9% excluding PABA; 1H NMR and Mass Spectral analyses for both crops were consistent with structure of the desired material 1-ethyl-(E,E)-2,6-bis[2-[4-(pyrrolidinyl)phenyl]ethenyl]pyridinium 4-aminobenzoate salt. This product is also named 1-ethyl-(E,E)-2,6-bis[2-[4-(pyrrolidinyl)phenyl]ethenyl]pyridinium p-aminobenzoate salt or 1-ethyl-(E,E)-2,6-bis[2-[4-(pyrrolidinyl)phenyl]ethenyl]pyridinium PABA salt.

Provenance & Evidence