Blazing goIITian
http://books.google.co.in/books?id=ega5c11VHvkC&pg=PA348&lpg=PA348&dq=NHCOCH3+activating+group+benzene&source=web&ots=tM1i0Qfyts&sig=jm6fsvwhPxg9zYDhBxmdvj2Rmzo&hl=en