Isopropyl acetate hydrolysis

Real Quaternary System Isopropyl Acetate Hydrolysis... 

Other potential synthetic methods include fermentation (qv) of certain carbohydrates (qv), oxidation of propane, hydrogenation of acetone, and hydrolysis of isopropyl acetate. The hydrogenation of by-product acetone is the only method practiced commercially. 

The trends of variation of the activation parameters are correlated with the solvation mechanism and dielectric behavior of the medium. Thus, AH, AG and A5 for the acidic resin-catalyzed hydrolysis of isopropyl acetate were calculated using the Wynne-Jones and Eyr-... 

Fig. 6. Yates-McClelland plot of the rate coefficients for hydrolysis of protonated benzyl and isopropyl acetates in sulphuric acid solutions, against the activity of water. Data for t-bulyl acetate...

This technique and these results have been extended in a very complete investigation by Yates and McClelland37. These authors have measured the rates of hydrolysis of eight representative acetate esters in 10-100% sulphuric acid some of their results are plotted in Fig. 1, (p. 74.) Yates and McClelland also measured the protonation behaviour of three of the esters in the same medium, by the spectrophotometric method (p. 70). They found that the basicities of the three esters, methyl, -propyl and isopropyl acetate, are closely similar, and that their protonation behaviour is described by the equation37... 

He encouraged the use of isopropyl acetate (b.p. 89°C) instead of ethyl acetate (b.p. 77°C) because of its reduced water solubility and greater stability to hydrolysis. He preceded the phase transfer catalysis era using detergents to speed reaction rates and increase yields. His bag of tricks, as he would whimsically refer to his armory of techniques, was an eye opener for his more conventional disciples. 

The hydrolysis of isopropyl acetate (IPOAc) to acetic acid (HOAc) and isopropanol (IPA) is a reversible reaction ... 

Isopropyl acetate (IPAc) is much more resistant to hydrolysis than EtOAc in the preparation of the methanesulfonate salts 3 (Figure 4.3) significant amounts of the acetic acid solvates were formed when the solvent was EtOAc, and IPAc was preferred [12], Crixivan intermediate 4 was prepared under Schotten-Baumann conditions by using IPAc at elevated temperatures (Figure 4.4) [13], which suggests the resistance of IPAc to hydrolysis. 

In situ product separation by distillation offers applications in esterification (e.g., for ethyl acetate), trans-esterification (e.g., for butyl acetate), hydrolysis (e.g., for ethylene glycol, isopropyl alcohol), metathesis (e.g., for methyl oleate), etherification (e.g., for MTBE, ETBE, TAME), and alkylation reactions (e.g., for cumene). 

Poor decanter phase separation resulted fiom slow hydrolysis of isopropyl acetate to isoiHtipanoI, which was soluble in both organic and aqueous phases... 

Cyclopropyl thien-2-yl ketone (34), available commercially, was subjected to a Grignard reaction with 21 to yield a carbinol (31) in excellent yield. Bromotrimeth-ylsilane-mediated opening of the cyclopropyl ring led to the 4-bromo derivative 32. Condensation with ethyl i -(-)-pipeildme-3-carboxylate (16) was conducted in isopropyl acetate as a solvent with anhydrous lithium carbonate as the base. The transformation was cleaner and did not provide any of the diene (26) arising from elimination of hydrogen bromide. The alkylation of the nipecotate residue could also be directly effected with a mixture of the tartrate salt of 16, lithium carbonate, and isopropyl acetate. Compound 33 was readily isolated as the hydrochloride isopropyl acetate was superior to all other solvents used in this reaction. Since it is not itself prone to hydrolysis, it is preferable to ethyl acetate. Moreover, it appears to crystallize hydrochlorides much better. 

Isopropyl acetate, and not ethyl acetate or vinyl acetate, is thus the more suitable model compound for considering the hydrolysis of poly(vinyl acetate) with sodium hydroxide in acetone / water (75 25) at 30° C, as can be seen from the rate constants ... 

Esters react with water under either acid or base conditions to give the acid, but the leaving group is now RO rather than Cl or O2CR, as in the previous reactions with acid chlorides or acid anhydrides. For basic hydrolysis conditions, the experiment requires two steps to convert the ester to the acid. Isopropyl acetate (19), for example, is heated to reflux in aqueous NaOH... 

Many carbamates have been used as protective groups. They are arranged in this chapter in order of increasing complexity of stmcture. The most useful compounds do not necessarily have the simplest stmctures, but are /-butyl (BOC), readily cleaved by acidic hydrolysis benzyl (Cbz or Z), cleaved by catalytic hy-drogenolysis 2,4-dichlorobenzyl, stable to the acid-catalyzed hydrolysis of benzyl and /-butyl carbamates 2-(biphenylyl)isopropyl, cleaved more easily than /-butyl carbamate by dilute acetic acid 9-fluorenylmethyl, cleaved by /3-elimination with base isonicotinyl, cleaved by reduction with zinc in acetic acid 1-adamantyl, readily cleaved by trifluoroacetic acid and ally], readily cleaved by Pd-catalyzed isomerisation. 

Dichloroquinoxalme (191) and isopropyl 2-lithio-2-methoxy-2-( 1-methoxy-l-methylethoxy)acetate (192) (prepared in situ) gave the mixed ketal intermediate (194) that underwent gentle acid hydrolysis to afford 2-chloro-3-propoxyoxaloquinoxaline (193) [THF-(Me2NO)3PO, —78°C 20°C then 2M HCl, 25°C, 20 min 90%]. ... 

In degree 2 only reactivity degrees are treated vis- i-vis exothermic polymerization in particular and addition reactions on the double bond (ethylene, butadiene, styrene, propylene), easy peroxidation (isopropyl oxide, acetaldehyde), hydrolysis (acetic anhydride). Possibly only propionitrile and substances with code 0 have an actual NFPA stability code. Every time one has to deal with the NFPA code one has to interpret it after carefully reading the paragraphs in Part Two. 

The use of a lipophilic zinc(II) macrocycle complex, 1-hexadecyl-1,4,7,10-tetraazacyclododecane, to catalyze hydrolysis of lipophilic esters, both phosphate and carboxy (425), links this Section to the previous Section. Here, and in studies of the catalysis of hydrolysis of 4-nitrophenyl acetate by the Zn2+ and Co2+ complexes of tris(4,5-di-n-propyl-2 -imidazolyl)phosphine (426) and of a phosphate triester, a phos-phonate diester, and O-isopropyl methylfluorophosphonate (Sarin) by [Cu(A(A(A/,-trimethyl-A/,-tetradecylethylenediamine)l (427), various micellar effects have been brought into play. Catalysis of carboxylic ester hydrolysis is more effectively catalyzed by A"-methylimidazole-functionalized gold nanoparticles than by micellar catalysis (428). Other reports on mechanisms of metal-assisted carboxy ester hydrolyses deal with copper(II) (429), zinc(II) (430,431), and palladium(II) (432). 

A comparison of the kinetics of alkaline hydrolysis of methyl, isopropyl and butyl acetates in propan-2-ol-water and t-butanol-water has revealed that the observed effects correlate with solvent structure. ... 

Chemical/Physical. Hydrolyzes in water forming isopropyl alcohol and acetic acid (Morrison and Boyd, 1971). The estimated hydrolysis half-life at 25 °C and pH 7 is 8.4 yr (Mabey and Mill, 1978). 

In contrast, 2-methylcyclohexanone and 2-methylindanone were racemized during imine hydrolysis with sodium acetate/acetic acid/pentanc/water8. In the preparation of 2-isopropyIcy-clohexanone and 2-isopropyl-6-methylcyclohexanone enantiomeric excess of the final products was low due to racemization8. 

The product (15-2) from aldol condensation of meto-nitrobenzaldehyde with the dimethyl acetal from ethyl 4-formylacetoacetate (15-1) provides the starting material for a dihydropyridine in which one of the methyl groups is replaced by a nitrile. Reaction of (15-2) with the eneamine from isopropyl acetoacetate gives the corresponding dihydropyridine hydrolysis of the acetal function with aqueous acid affords the aldehyde (15-3). That function is then converted to its oxime (15-4) by reaction with hydroxylamine. Treatment of that intermediate with hot acetic acid leads the oxime to dehydrate to a nitrile. There is this obtained nilvadipine (15-5) [16]. 

Isopropyl-2-phenylcyclobutanol (29) was obtained by hydroboration-oxidation of 4-iso-propyl-l-phenylcyclobutene.38 In a synthetically useful procedure, hydrolysis of 1,2-bis(phenylsulfanyl)cyclobutene at room temperature in a solution of copper(IT) chloride and titanium(IV) chloride in acetic acid gave 2-(phenylsulfanyl)cyclobutanone (30) in 85% yield.39... 

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