The prerequisites for using Azure AD Connect don't list Server 2012 R2 Essentials, but they do list Server 2012 R2. Normally I understand pre-requisites just fine, but I'm not sure about the differences in this case between Server 2012 R2 and Server 2012 R2 Essentials.
https://www.microsoft.com/en-us/download/details.aspx?id=47594
Would Server 2012 R2 Essentials be compatible with Azure AD Connect? Thanks