using System;

using RestSharp;

public class Program

{

    public static void Main()

    {

        try 

        {

            var client = new RestClient("https://login.microsoftonline.com/affc029f-c2fb-498b-95ee-3f5341dbdfa6/oauth2/token");

            client.Timeout = -1;

            var request = new RestRequest(Method.POST);

            request.AddHeader("Cookie", "buid=0.ATEAnwL8r_vCi0mV7j9TQdvfphUAAAAAAAAAwAAAAAAAAAAxAAA.AQABAAEAAAB2UyzwtQEKR7-rWbgdcBZImUmtLrB7hHiD4gT7dfsYTLn_nsvqqg9VVhgPpRLYv--dLKQAKiMQHHQ4WLzQaQTtzU9qbZrlHJQnH_3bFTV8g9qToNAdZk9-bkR8uqREiOsgAA; x-ms-gateway-slice=estsfd; stsservicecookie=estsfd; fpc=AiJY7HoUdxhAthTM8XtDw2fSGl97AQAAAAgvbNcOAAAA");

            request.AlwaysMultipartFormData = true;

            request.AddParameter("grant_type", "client_credentials");

            request.AddParameter("client_id", "508ab7d4-a3b9-4fb6-be1c-82088600ec40");

            request.AddParameter("client_secret", "2WZ51DFC.f_5S44LtwzVEIPa_3top~ipgL");

            request.AddParameter("resource", "https://ald-sb.sandbox.operations.dynamics.com");

            IRestResponse response = client.Execute(request);

​

            if ( response.IsSuccessful )

                Console.WriteLine("Connection is successful.");

            Console.WriteLine(response.Content);

        }

        catch ( System.Exception ex )

        {

            Console.WriteLine( string.Format("Error: {0}", ex ));

        }

    }

}