Connect to 12c Docker container from different container

Hello,

I'm using 12c container from https://hub.docker.com/_/oracle-database-enterprise-edition

and I'm starting container with:

docker run \

    --rm -it -p 1521:1521 -p 5500:5500 \

    --name oracle12c -h oracle12c \

    -v /var/lib/docker/volumes/PV/ORCL:/ORCL \

    --network-alias oracle12c store/oracle/database-enterprise:12.2.0.1

Docker 12c container is running fine but I can't figure how can I connect to it from different container...

Below connection strings work inside 12c container but doesn't from different container:

docker exec -it oracle12c /bin/bash

sqlplus "sys/Oradoc_db1@oracle12c:1521/ORCLCDB.localdomain as sysdba"

sqlplus "system/Oradoc_db1@oracle12c:1521/ORCLCDB.localdomain"

Below connection strings DO NOT work inside 12c container and password is asked: