Various indolines suitable for use in Schemes 1 and 2 above can be conveniently obtained by reduction of the corresponding indole analogs using a reducing agent such as sodium cyanoborohydride, sodium triacetoxyborohydride or triethylsilane in a suitable solvent such as dichloromethane or dichloroethane in the presence of an acid, such as acetic acid or trifluoroacetic acid.