6'-Diethylamino-3-oxo-2'-phenylaminospiro(isobenzofuran-1(3H),9'(9H)xanthene)-5-carboxylic acid 71799-72-9 Spiro(isobenzofuran-1(3H),9'-(9H)xanthene)-5-carboxylic acid, 6'-(diethylamino)-3-oxo-2'-(phenylamino)-