Aminimides. I. A general synthesis of aminimides from acyl hydrazides and their pyrolysis

Abstract

Acyclic, alicyclic, and aromatic bis-trimethylaminimides and a keto-substituted trimethylaminimide have been synthesized by a stepwise route of general applicability. Pyrolysis of the aliphatic aminimides resulted in a rearrangement to trimethylamine and isocyanate. The keto-isocyanate herein reported was synthesized in a convenient four-step sequence from dimethyl ketene dimer in a good yield, and provides an attractive new route to this type of difunctional compound. Pyrolysis of the bis-aminimides in the presence of polyhydroxylic materials gave polyurethanes.

Chemistry of aminimides

“…4. Preparation from Trialkylaminimines, 3 +-1,1,1-Trimethylhydrazinium halides (47) when treated with a strong base such as phenyllithium in ether,71 potassium amide in liquid ammonia, or potassium ferf-butoxide in ferf-butyl alcohol and tetrahydrofuran form trimethylaminimine (48). 72 The product from the second (CH3)3N-NH2 X" -(CH3)3N-ÑH 47 48 method is the parent compound which is hygroscopic and unstable.…”

Synthetic Approaches to Acyl Hydrazides and Their Use as Synthons in Organic Synthesis

“…More specifically, in situ formation of the acyl hydrazide salt 111 from 110 was followed by treatment with basic conditions, which underwent a condensation reaction at high temperature, leading to the desired triphenyl isocyanurate (112) (Scheme 29). 39…”

Pyrolysis of hydrazine derivatives and related compounds with N N single bonds

“…Pyrolysis of these aminimides 163 in the solid state or in solution at temperatures of~200 o C liberates the amines, usually trimethylamine, and the isocyanates are obtained in good yields (e.g. 75-80 %) (Scheme 45) [143,144,145,146].…”