Benzodiazepine derivatives represented by the following general formula or pharmaceutically acceptable salts thereof:
wherein
R1 is -COR4 (R4 is a carboxylic acid residue) or an alkyl or aralkyl group (these groups have a substituent selected from a carboxyl group, an amino group and a cyano group), R2 is a lower alkyl group and R3 is a hydrogen atom or a lower alkyl group.
The above compounds are low in toxicity and have antitumor activity.