its pretty interesting did u ever try?
Anyway the key is just to drop h2so4 until ether layer doesn't go green anymore und there is no yellow precipitate going down. After this the top
layer will start to chance the color to a kind of orange. Thats the point to stop or better a bit further. Cooling was applied during beginning of
addition. Yield of pseudonitrosite was 60-62% with this method.
just half of volume (h2so4) was needed. Good washing of pseudonitrosite is essential because naso4 is pretty but solvable in water.