Photolytic degradation of frusemide.

Irradiation with 365 nm u.v. light of frusemide (4-chloro-N-furfuryl-5-sulphamoyl-anthranilic acid) in methanol results primarily in photoreduction to N-furfuryl-5-sulphamoylanthranilic acid and photohydrolysis to 4-chloro-5-sulphamoylanthranilic acid (saluamine).