- Preparation method of azodiisobutyrate
-
The invention discloses a preparation method of azodiisobutyrate. The preparation method mainly includes the steps of adding azodiisobutyronitrile, alcohol (R-OH), solvents and ion exchange resins into a reactor with stirring, reacting at a specific temperature for a period of time, and filtering to remove the ion exchange resins; concentrating filtrate and removing the solvents so as to obtain the azodiisobutyrate shown as structural formula in the description, wherein R can be methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, hexyl, isooctyl, dodecyl, cetyl and octadecyl. With the ion exchange resins as a catalyst, the preparation method is convenient to implement and for after-treatment, environment friendly and little corrosive to equipment, and the catalyst is reusable, high in conversion rate and simple in process.
- -
-
Paragraph 0018
(2017/10/07)
-
- Process for preparing azoiminoethers and azocarboxylic acid esters and novel azocboxylic acid mixed esters
-
The invention concerns a method for preparing an azoiminoether hydrochloride which consists in reacting an azonitrile with an alcohol and hydrochloric acid in an aromatic solvent, wherein the molar ratio R=HCl/azonitrile is >2 when the alcohol is methanol and >3 when the alcohol is ethanol or a higher alcohol. The invention also concerns a method for preparing an azocarboxylic acid ester which consists in the synthesis of an azoiminoether hydrochloride by the inventive method and, hydrolysis in the presence of the resulting azoiminoether hydrochloride. Said methods enable to obtain liquid composition of azocarboxylic acid esters. The invention further concerns mixed azoiminoether salts of formula (II′). The invention also concerns mixed azoiminocarboxylic acid esters corresponding to the formula (III′).
- -
-
Page column 9
(2010/11/30)
-
- The Self-Reactions of 1-Methoxycarbonyl-1-methylethyl and Higher Ester Radicals: Combination vs Disproportionation and Oligomeric Products from Secondary Reactions
-
The geminate self-reactions of the title methyl, ethyl and butyl ester radicals (2a-c), formed by decomposition of the corresponding azo precursors (1a-c) in the presence of stable nitroxide radical scavengers, were found on the basis of product analysis to comprise combination and disproportionation in the ratios 56 : 44 (methyl), 58 : 42 (ethyl) and 47 : 53 (butyl).In the absence of radical scavengers, extensive oligomerization is observed.Hydrogenation and degradation were used in conjunction with g.l.c.-m.s. to deduce the identities of the dimeric, trimeric and tetrameric products, which were in most cases subsequently confirmed by isolation and n.m.r. analysis.Of particular interest is the highly regioselective disproportionation of radical (3) to give dimethyl 4-methylpent-1-ene-2,4-dicarboxylate (8), and the further reaction of (8) with (2a) to form branched oligomers (10) and (15).
- Bizilj, Snezna,Kelly, David P.,Serelis, Algirdas K.,Solomon, David H.,White, Kathleen E.
-
p. 1657 - 1673
(2007/10/02)
-