Mesityl oxide synthesis

A number of dihydroquinolines have been prepared by treating aniline derivatives with acetone or mesityl oxide in the presence of iodine. In these cases aromatization to the fully unsaturated quinoline would require the loss of methane, a process known as the Riehm quinoline synthesis. Such Skraup/Doebner-von Miller-type reactions are often low yielding due to large amounts of competing polymerization. For example, aniline 37 reacts with mesityl oxide to give dihydroquinolines 39, albeit in low yield. ... 

Enone (37) is mesityl oxide, the aldol dimer of acetone (p T 150), In this synthesis, the Nef hydrolysis... 

It is often said that the property of acidity is manifest only in the presence of a base, and NMR studies of probe molecules became common following studies of amines by Ellis [4] and Maciel [5, 6] and phosphines by Lunsford [7] in the early to mid 80s. More recently, the maturation of variable temperature MAS NMR has permitted the study of reactive probe molecules which are revealing not only in themselves but also in the intermediates and products that they form on the solid acid. We carried out detailed studies of aldol reactions in zeolites beginning with the early 1993 report of the synthesis of crotonaldehyde from acetaldehyde in HZSM-5 [8] and continuing through investigations of acetone, cyclopentanone [9] and propanal [10], The formation of mesityl oxide 1, from dimerization and dehydration of... 

A Catalytic Distillation Process for the One Step Synthesis of Methyl Isobutyl Ketone from Acetone Liquid Phase Kinetics of the Hydrogenation of Mesityl Oxide... 

The present economic and environmental incentives for the development of a viable one-step process for MIBK production provide an excellent opportunity for the application of catalytic distillation (CD) technology. Here, the use of CD technology for the synthesis of MIBK from acetone is described and recent progress on this process development is reported. Specifically, the results of a study on the liquid phase kinetics of the liquid phase hydrogenation of mesityl oxide (MO) in acetone are presented. Our preliminary spectroscopic results suggest that MO exists as a diadsorbed species with both the carbonyl and olefin groups coordinated to the catalyst. An empirical kinetic model was developed which will be incorporated into our three-phase non-equilibrium rate-based model for the simulation of yield and selectivity for the one step synthesis of MIBK via CD. 

Amines, thiols, eOH (p. 226), etc., will also add to the 0-carbon atom of 0-unsaturated carbonyl compounds and esters, but the most important reactions of C=C—C=0 systems are in Michael reactions with carbanions reactions in which carbon-carbon bonds are formed. A good example is the synthesis of l,l-dimethylcyclohexan-3,5-dione (dimedone, 100) starting from 2-methylpent-2-ene-4-one (mesityl oxide, 101) and the carbanion 0CH(CO2Et)2 ... 

Used industrially for organic synthesis as an antifoam agent, as a stabilizer for mesityl oxide and as a chemical intermediate for detergents dyes pesticides and pharmaceuticals. 

One of the most thoroughly investigated aldol condensations is the selfcondensation of acetone. This is an important industrial reaction for the production of diacetone alcohol (DA) (Scheme 11), which is valuable as a chloride-free solvent and an intermediate in the synthesis of industrially important products such as mesityl oxide (MO), isophorone, methyl isobutyl ketone, and 3,5-xylenol. The reaction is exothermic, with the yield of DA decreasing with increasing reaction temperature it is usually performed with NaOH or KOH as a basic catalyst 118). 

The preparation of iV-nitroso-/5-alkylaminoisobutyl ketones is of particular interest as a method for preparing the intermediates for the diazoalkane synthesis. The preparation of these compounds is based on the addition of a primary amine to mesityl oxide to give a secondary amino ketone which is then nitrosated (see Volume I, Chapter 15, Section 2A,g). This preparation uses an... 

Improvements in the double Skraup synthesis of 1,7-phenanthroline from m-phenylenediamine now enable a yield of 70% to be achieved.163 The Skraup reaction continues to be used for the synthesis of 1,7-phen-anthrolines starting from the substituted 5-aminoquinolines. S-Chloro-6-hydroxy-1,7-phenanthroline (18) has been prepared in this way,164 and an improved synthesis of 6-hydroxy-1,7-phenanthroline was reported.165 As expected, the Skraup reaction on 5-aminoquinaldine affords 8-methyl-1,7-phenanthroline,166 not 2-methyl-1,7-phenanthroline as it was previously named.8 The extension of the Skraup reaction using methyl vinyl ketone instead of glycerol has been applied to 5-aminoquinoline to afford 4-methyl-1,7-phenanthroline.166 A related condensation using 2-hydroxymethylenecyclohexanone provides a route to benzo-substituted 1,7-phenanthrolines.167 7-Aminoquinoline with mesityl oxide in the presence of iodine gives 8,8,10-trimethyl-7,8-dihydro-l,7-phenanthroline (19).168... 

Frequently the basic conditions used cause the initial Michael adduct to undergo intramolecular transformations, as for example in the synthesis of dimedone (Expt 7.11). This involves a Michael reaction between mesityl oxide and diethyl malonate followed by an internal Claisen ester condensation. 

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