Science of Synthesis

Mourad, A. K.; Czekelius, C., Science of Synthesis Knowledge Updates, (2011) 3, 88.

Carboxylic hydrazides are stable under common hydrolytic conditions and require oxidative activation before an alcohol can attack to form the corresponding ester. Oxidation can be achieved using bromine,[‌87‌] ammonium cerium(IV) nitrate,[‌88‌] thallium salts,[‌89‌,‌90‌] copper salts,[‌91‌–‌93‌] or hypervalent iodine compounds (‌Table 8‌).[‌94‌,‌95‌] Illustrative examples include the formation of ethyl 4-nitrobenzoate (‌22‌) from 4-nitrobenzoic hydrazide (‌21‌) using thallium(III) nitrate, and the synthesis of ethyl benzoate (‌24‌) from benzoic 2-tosylhydrazide (‌23‌) mediated by copper(II) chloride. The intermediate formation of an acyl diazo compound is assumed.[‌96‌] Primary and substituted hydrazides undergo the process at low temperatures rendering this method efficient and broadly applicable.

‌Meeee 8‌ Meeee Meeeeeeee eeee Meeeeeeeee[‌88‌–‌88‌,‌88‌,‌88‌]

Meeeeeee Meeeeeee	Meeeeee/Meeeeeeeee	Meeeeee	Meeee (%)	Mee
	MeMM, MMM, ee		88	[‌88‌]
	MeMM, Me(MM8)8		88	[‌88‌]
	MeMM, Me(MM8)8, ee		88	[‌88‌]
	e-MeMMe, MeMe8, MMM, ee		88	[‌88‌]
	MeMM, MeMe8, M8M, MMM, ee		88	[‌88‌]
	MeMM, MMM,e MMMe8, ee		88	[‌88‌]

e MMM = 8-eeeeeee-8,8-eeeeeeeeeee-8(8M)-eee 8-eeeee (8-eeeeeeeeeeee eeee).

Meeeeeeeeeee Meeeeeeee

Meeee 8-Meeeeeeeeeeee (‌88‌); Meeeeee Meeeeeeee Meeee Meeeeeee(MMM) Meeeeee:[‌88‌]

MMMMMMM: Meeeeeee eeeee eee eeeee eeee eeeeeee, eeeeeeee, ee eeeeeeee eeeeeee eee eeee.

M eeee ee Me(MM8)8•8M8M (888 ee, 8.88 eeee) ee eee MeMM (8 eM) eee eeeee ee e eeeeeeeeee ee 8-eeeeeeeeeeee eeeeeeeee (‌88‌; 888 ee, 8.88 eeee) ee eee MeMM (8 eM), eee eee eeeeeee eee eeeeeee ee ee eee 8 e, eeeeeeeeeeee eeeee eeeeeee eeeeeeee, eeeeeee eeee M8M (8 eM), eee eeeeeeeeeee eeee MeMMM8. Mee eeeeeeeee eeeeeee eee eeeeeeeee eeee MMMe8 (8 × 88 eM), eee eee eeeeeeee eeeeeeee eeee eeeee (Me8MM8), eee eeeeeeeeeeee ee eeeeeee ee eeee eee eeeeeee; eeeee: 88 ee (88%).

Meeeeeeeee Meee Meeeee, e.e. ‌88‌; Meeeeee Meeeeeeee Meeee Meeeee(MM) Meeeeeee:[‌88‌]

M eeee ee MeMe8•8M8M (8.88 e, 8.88 eeee) ee MeMM (88 eM) eee eeeee ee e eeeeeee eeee ee eee eeee eeeeeeeee (e.e., ‌88‌) (8.88 eeee) ee MeMM (88 eM), eee eeeeeeee eee eeeeeeeee eee 88–88 e ee ee. Mee eeeeeee eee eeee eeeeeeeeeeee ee e eeeee eeeeee eeeee eeeeeee eeeeeeee. Mee eeeeeee eee eeeeeeeee eeee Me8M (88 eM) eee 88% ee MeMM (8 × 88 eM). Mee eeeeeee eeeee eee eeeeeeeee, eeeeee eeee M8M (8 × 88 eM), eeeee (Me8MM8), eee eeeeeeeeeeee eeeee eeeeeee eeeeeeee ee eeeeee eee eeeeeee ee eeeeeeeeeeee eeeeee. Mee eeeeeee eeeee ee eeeeeee eeeeeeee ee eeeeeeeeeeee.

References