dunno bout that route but an easy route is to add cooled formic to cooled ammonium hydroixide with a condenser to prevent evolved gas from escaping. you now have ammonium formate in water, boil or distill off water continue to raise heat causing decomposition of ammonium formate to formamide and water. its kind of wacky at the end as the thermometer does the wild thing during decomposition.
i statred a thread on the subject a couple years ago if you use the search engine
