Lewis-acid-induced electrophilic substitution in indoles with acetone. Part 2

The electrophilic substitution reaction of indole with acetone in the presence of boron trifluoride has been followed and the structures of two of the three products isolated have been established. The structure of compound (1), dimer II, was determined by X-ray diffraction methods as crystals from methanol were monoclinic, space group Cc, and had cell parameters a= 13.383(2), b= 14.064(2), c= 11.638(4)A, β= 114.74(2)°, Z= 4. The structure was refined to a final R value of 0.068.