Problem with ASP.NET WebService Application and Sharepoint 2013

Hi,

  I have a problem with VS2012. I would like to create ASP.NET WebService project and there is a template but it used framework 3.5. Unfortunatelly when I add reference to Sharepoint in this project and use sharepoint classes I got error:

Microsoft SharePoint is not supported in 32-bit process. Please verify that you are running in a 64-bit executable

ASP.NET WebService application uses default 3.5 framework. I change this project settings to 4.5 because sharepoint used that framework. Unfortunatelly when I run code and try to use sharepoint classes like (SPSite, SPWeb) I've got error as above. Please help how ASP.NET WebService works under VS2012 with sharepoint.