Look up this library on nuget. The NJsonSchema.CodeGeneration can be used to generate C# or TypeScript code from a JSON schema:
var generator = new CSharpGenerator(schema);
var file = generator.GenerateFile();
The file variable now contains the C# code for all the classes defined in the JSON schema.
I needed a class generated today but couldn't find any site that could convert json schema to c# classes online so used the above mentioned library and wrote something up quickly http://json2csharp.rohitl.com/ hope this helps.