I'm working on synthesis of organic nitrites, commonly used as special reagents for other syntheses.
The common reference of a organic nitrite synthesis is given in: Organic Syntheses, Vol. 16, p. 7 (1936); Coll. Vol. 2, p.108 (1943). This procedure is generally used with long-chain alcohols to produce the corresponding nitrite.
Sulphuric acid raises Tº from 0 to 70º C in less of 3 minutes, and this synthesis must be keep cold, due the decomposition of nitrous acid formed in situ and the competition of the elimination reaction. Cause of that, addition of acid must be very slow.
However, I accidentally used phosphoric acid in this reaction (due to a mistake of the chem store), obtaining the nitrite, but with higher yields that expected in less time.