Remember that you need formaldehyde as well, and that's not particularly easy to come by.
You won't need formaldehyde for salmiak. You need formaldehyde to produce methylamine with salmiak.
Methylamine from Ammonium Chloride and Formaldehyde (https://www.thevespiary.org/rhodium/Rhodium/clandestine/methylamine/)
(https://www.thevespiary.org/rhodium/Rhodium/clandestine/methylamine/)
it is very cool that you can purchase persulfate because you need an electro setup to make them yourself. what for? how about using a type of Elbs reaction? not just limited to p-OH'ing phenol, this will turn salicylaldehyde into gentisaldehyde(mp99C) in 50% yield. so? the dimethyl ether of gentisaldehyde is 2,5-dimethoxybenzaldehyde, which is a molecule of hi-test karma. of course you'll need to change the ammonium into the potassium salt but given the low solubility of the K(1.77g/100gH2O) a simple exchange w/KCl is worth a try. especially since this is the best way to make 2,5 dihydroxy cpds even with the low yields. just reflux w/alkali and K persulfate and clean up as usual. unreacted salicylaldehyde is easily separated as it is the only liquid-at-RT OH aldehyde. also the more OH's on a molecule-the more sol. in polar solvs/fewer OH's more sol in nonpolar solvs.
persulfate ion will also turn Cr+3 to +6(in alkali soln), Mn+2 to MnO2, K ferro- and ferricyanides to HCN(in mineral acids), and X- to X2(some iodate if conditions harsh)--Fe+2, Cu+2, and especially both in combo are catalysts for free halide production. it will also turn salicylic acid to gentisic acid. given the fact that salicylaldehyde is so easily made from phenol/NaOH/chloroform(albeit lo yield), you'd think someone would bee looking for a lot of Br2, methyl sulfate, and nitromethane. just a fyi for those who dont UTFSE, or were doing bong hits while reading their textbooks. of course i dont condone use of these precursors to make anything until the apocalypse and second coming, in which case it would b cool to drop some nexus.
bongmaster messiah is coming-prepare