Write JSON object in a column using the REST API

I need to store an entire JSON object in column named ccc_jsoncontent with type nvarchar(max) on a custom table using the REST API

For that i trigger a POST request to /api/entity/<tablename> with this body:

{
"values": { 

             "ccc_jsoncontent": [{"CCC_FirstName":"new","CCC_LastName":"new","CCC_Initials":"new","CCC_Location":"new"}]

           }
}

The object is written but all the doublequotes characteres " in the JSON object are deleted: [{CCC_FirstName:new,CCC_LastName:new,CCC_Initials:new,CCC_Location:new}]

, this means the JSON becomes non parseable fro the coming steps

Any idea on how to tackle this topic ?