Preparation of 2-methylbenzenediazonium
100 ml of concentrated hydrochloric acid (1.2 moles) and 50 ml of water are poured into a 500 ml flask. 43 grams (or 43 ml) of o-toluidine (0.4 mole) are added and well mixed in order to convert the o-toluidine into the o-toluidine hydrochloride. The solution is cooled with shaking in a salt-ice bath and the o-toluidine hydrochloride separates as fine crystals. By keeping the mixture at a temperature of 0-5° C and by vigorous shaking in the salt-ice bath the o-toluidine hydrochloride is treated with a solution of 28 grams of sodium nitrite in 80 ml of water with shaking. The o-toluidine hydrochloride dissolves as the more soluble 2-methylbenzenediazonium diazonium salt is formed, and at the end of the addition of the sodium nitrite the solution should contain a trace of nitrous acid. 2-methylbenzenediazonium is not stable and should be consumed.
Experiments in Organic Chemistry, L. F. Fieser, 215-216, 1941
2-methylbenzenediazonium, AC1Q4PVD, Benzenediazonium, methyl-, AC1L4V2Z, SCHEMBL6449318, CTK0J2604, AR-1E3857, 27457-43-8
2-Toluenediazonium, CID192837, 7017-88-1, 90558-65-9