In the interim meaning 'in the meanwhile'

Hi

Would you say that in the interim and in the meanwhile are equally natural and synonymous in these sentences?

1. Despite everything that had happened in the interim, we had remained good friends.
2. Despite everything that had happened in the meanwhile, we had remained good friends.

Or

1. My new job does not start until May, so I will continue in the old job in the interim.
2. My new job does not start until May, so I will continue in the old job in the meanwhile.

Thanks,

Tom