In Following code user is output which you want to send in JSON format:
System.Web.Script.Serialization.JavaScriptSerializer js = new System.Web.Script.Serialization.JavaScriptSerializer();
var data = js.Serialize(users).Replace("\"\\/Date(","").Replace(")\\/\"", "");
var output = js.DeserializeObject(data)
previous output:
{"name":"Amit Choudhary","dob":"/Date(1485256523000)/"}
new output:
{"name":"Amit Choudhary","dob":1485256523000}