Science of Synthesis

Brigas, A. F., Science of Synthesis, (2004) 13, 904.

Tetrazoles are weak bases, pKa −3 to −4, and can be protonated by addition of sulfuric acid. As predicted by calculations,[‌239‌] protonation occurs preferentially at N4; this is similar to what is generally observed with alkylation, e.g. formation of ‌92‌ (‌Scheme 66‌).[‌152‌,‌240‌,‌241‌] For example, 2,5-diaryltetrazoles react with dimethyl sulfate at 80°C to give high yields of the corresponding 4N-methyl-quaternized tetrazole. The structure of the substituents, e.g. 5-substituted 1-vinyltetrazoles, and the nature or size of the alkylating agent can lead to some alkylation at N3.[‌242‌,‌243‌]

‌Meeeee 88‌ Meeeeeeeeeeeee ee Meeeeeeee Meeeeeee[‌888‌]

Meeeeeeeeeee Meeeeeeee

8-Meeee-8-eeeeee-8-(eeeeeeeeeeeee)-8M-eeeeeeee-8-eee Meeeeee (‌88‌):[‌888‌]

M eeeeeeee ee eeeeeeee eeeeeee (8.88 e, 88 eeee) eee 8-eeeeee-8M-eeeeeeee-8-eeeee (8.88 e, 88 eeee) ee MeMM8 (888 eM) eee eeeeee ee 88°M eee 8 e. Mee eeeeeee eee eeeeee ee 8°M eee 88 e eee eee eeeeeeeeeee eeeeeeee eee; eeeeeeeeeeeee ee eee eeeeeeee ee eeee eee eeeeee eee eeeeeeee ee 8°M eeee e eeeeee eeee. Meee eeeeeeeee eeee eeeeee eeee Me8M eee eeeeeeeeeeeeee (MeMM/Me8M) ee eeee eee eeeeeee ee eee eeeeeeeeeee; eeeee: 8.88 e (88%); ee 888°M (eee).

References

Meeeeee Meeeeeeeeee

• 8.Meeeee-Meee, (8888) M 8e, 888.