1: [Cy5]-Naltrexone With hydroxymethylphenoxyethyl resin; triphenylphosphine; diethylazodicarboxylate in tetrahydrofuran; toluene T=20°C; 1 h; 2: N-phenylhydrazine monohydrochloride With 4 A molecular sieve; acetic acid in dichloromethane T=20°C; Fischer indole synthesis; 1 h; 3: With trifluoroacetic acid in dichloromethane T=20°C; 0.5 h;

in water Fischer indole synthesis; 1.5 h; Reflux;

(i) NaH, DMSO, (ii) /BRN= 3596648/, (iii) aq. HCl; Multistep reaction;

in 1-methyl-pyrrolidin-2-one T=20 - 65°C; Inert atmosphere; Product distribution / selectivity;

1: With hydrazine in N,N-dimethyl-formamide T=100°C; 2: With methanesulfonic acid in dimethyl sulfoxide T=130°C;

1: 78 percent / K2CO3 / dimethylformamide 2: 58 percent / TsOH*H2O / ethanol / Heating View Scheme

hydrogenchloride in water; acetonitrile