Thanks for asking question! As its mentioned here: Synonyms in Azure Cognitive Search that-
Synonyms are analyzed during query processing. If you need to define synonyms that contain commas or other special characters, you can escape them with a backslash, like in this example:
{
"format": "solr",
"synonyms": "WA\, USA, WA, Washington\n"
}
Since the backslash is itself a special character in other languages like JSON and C#, you will probably need to double-escape it. For example, the JSON sent to the REST API for the above synonym map would look like this:
{
"format":"solr",
"synonyms": "WA\, USA, WA, Washington"
}
If you are looking more on this? Let us know if further query on this.