3-(3-Oxo-1H,3H-naphtho(1,8-cd)pyran-1-ylidene)-3H-indole-7-carboxylic acid hydrochloride 3H-Indole-7-carboxylic acid, 3-(3-oxo-1H,3H-naphtho(1,8-cd)pyran-1-ylidene)-, hydrochloride 58556-60-8 EINECS 261-325-3