using System;

using System.Linq;

using Newtonsoft.Json.Linq;

public class Program

{

    public static void Main()

    {

        string json = @"

            {

              ""memberdetails"": [

                {

                  ""id"": 0,

                  ""label"": ""General Details"",

                  ""visible"": true,

                  ""properties"": [

                    {

                      ""label"": ""Address"",

                      ""description"": ""Residential or Postal Address"",

                      ""view"": ""textarea"",

                      ""config"": {},

                      ""hideLabel"": false,

                      ""validation"": {

                        ""mandatory"": false,

                        ""pattern"": null

                      },

                      ""id"": 0,

                      ""value"": ""test 1"",

                      ""alias"": ""address"",

                      ""editor"": ""Umbraco.TextboxMultiple"",

                      ""visible"": ""true""

                    },

                    {

                      ""label"": ""State"",

                      ""description"": ""State of residence"",

                      ""view"": ""textbox"",

                      ""config"": {},

                      ""hideLabel"": false,

                      ""validation"": {

                        ""mandatory"": false,

                        ""pattern"": null

                      },

                      ""id"": 0,

                      ""value"": ""test 2"",

                      ""alias"": ""state"",

                      ""editor"": ""Umbraco.Textbox"",

                      ""visible"": ""true""

                    }

                  ]

                }

              ]

            }";

        JObject obj = JObject.Parse(json);

        JArray result = new JArray(

            obj.SelectToken("memberdetails[0].properties")

               .Select(jt => new JObject(new JProperty((string)jt["alias"],jt["value"]))));

        Console.WriteLine(result.ToString());

    }

}