6'-Diethylamino-3-oxo-2'-phenylaminospiro(isobenzofuran-1(3H),9'(9H)xanthene)-6-carboxylic acid 71799-71-8 Spiro(isobenzofuran-1(3H),9'-(9H)xanthene)-6-carboxylic acid, 6'-(diethylamino)-3-oxo-2'-(phenylamino)-