Abstract:
In a previous paper, it was reported by one of us that bis-(
β-chloroethyl)-amino- indole-2-carboxylic acids (I
a-c) were found to have pronounced antitumour activity. For the purpose of studying the relationships between chemical structures and antitumour acti- vities of I
a-c and also of searching for new antitumour agents, in the present paper, N- acetyl-N-3-bis-(
β-chloroethyl)-amino-6-methyl-phenyl-glycine (III
a) has been pre- pared. III
a may be considered as the ring-cleft product of the 6-bis-(
β-chloroethyl)- amino-indole-2-carboxylic acid (I
b) at the position a. Two demethyl analogues, N- acetyl-N- 3-bis-(
β-chloroethyl)-amino -phenyl-glycine (III
b) and N-acetyl-N-4-bis- (
β-chloroethyl)-amino -phenyl-glycine (III
c) have also been prepared and they can also be regarded as the ring-cleft products at the positions a and b of I
a and I
b respectively. Compounds III
a-b were prepared by a six-step synthesis, the sequence of reactions is described in the Chinese text. The starting meterials of III
a-c employed were ethyl N-(nitro-phenyl)-glycinates (VI
a-c) which were conveniently prepared by the condensa- tion of the corresponding nitro-anilines and ethyl chloroacetate or ethyl bromoacetate in the presence of sodium carbonate and sodium iodide in dimethylformamide. VI
a-c were acylated with acetic anhydride to give VII
a-c, which were subjected to catalytic hydrogena- tion in the presence of Raney-Ni or Pd-C to give N-acetyl-N-(amino-phenyl)-glycinates (VIII
a-c). The latters were treated with a solution of ethylene oxide in dilute acetic acid to yield N-acetyl-N-bis-(
β-hydroxyethyl)-amino-phenyl-glycinates (IX
a-c) which afforded III
a-c on chlorination with phosphorus oxychloride, hydrolysis with 6 N hydro- chloric acid, and acetylation. Pharmacological studies showed that compound III
a possessed marked antitumour activity against Sarcoma-180, but neither III
b nor III
c showed any significant activity against the same tumour.