57394-20-4Relevant academic research and scientific papers
2-Carboxy-4-oxo-4H,6H-(2)-benzopyrano-(3,4-f)-(1)-benzopyrans and esters and salts thereof
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, (2008/06/13)
Compounds of the formula SPC1 Wherein the R1 ' s are hydrogen, alkyl of 1 to 3 carbon atoms or together a double-bonded oxygen, R2 is hydrogen, fluorine, chlorine, methyl, hydroxyl, methoxy, hydroxy-ethoxy, nitro or --SO3 H, R3 is hydrogen, fluorine, chlorine or methoxy, R4 is hydrogen, methyl or methoxy, R5 is hydrogen, fluorine, chlorine or methyl, and R6 is hydrogen or alkyl of 1 to 8 carbon atoms, and, when R6 is hydrogen, salts thereof formed with an inorganic or organic base; the compounds as well as the salts are useful as antiallergics.
