c# allows you to use dictionaries with keys that are case insensitive, so a workaround I've used is to convert the JObject to a dictionary with StringComparer.CurrentCultureIgnoreCase
set, like so:
JObject json = (JObject)JsonConvert.DeserializeObject(ptString);
Dictionary<string, object> d = new Dictionary<string, object>(json.ToObject<IDictionary<string, object>>(), StringComparer.CurrentCultureIgnoreCase);
String f = d["FROM"].ToString();
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