Butanone purification

Another attractive commercial route to MEK is via direct oxidation of / -butenes (34—39) in a reaction analogous to the Wacker-Hoechst process for acetaldehyde production via ethylene oxidation. In the Wacker-Hoechst process the oxidation of olefins is conducted in an aqueous solution containing palladium and copper chlorides. However, unlike acetaldehyde production, / -butene oxidation has not proved commercially successflil because chlorinated butanones and butyraldehyde by-products form which both reduce yields and compHcate product purification, and also because titanium-lined equipment is required to withstand chloride corrosion. 

The most recent, and probably most elegant, process for the asymmetric synthesis of (+)-estrone appHes a tandem Claisen rearrangement and intramolecular ene-reaction (Eig. 23). StereochemicaHy pure (185) is synthesized from (2R)-l,2-0-isopropyhdene-3-butanone in an overall yield of 86% in four chemical steps. Heating a toluene solution of (185), enol ether (187), and 2,6-dimethylphenol to 180°C in a sealed tube for 60 h produces (190) in 76% yield after purification. Ozonolysis of (190) followed by base-catalyzed epimerization of the C8a-hydrogen to a C8P-hydrogen (again similar to conversion of (175) to (176)) produces (184) in 46% yield from (190). Aldehyde (184) was converted to 9,11-dehydroestrone methyl ether (177) as discussed above. The overall yield of 9,11-dehydroestrone methyl ether (177) was 17% in five steps from 6-methoxy-l-tetralone (186) and (185) (201). 

The general purification methods listed for xylene are applicable. p-Xylene can readily be separated from its isomers by crystn from such solvents as MeOH, EtOH, isopropanol, acetone, butanone, toluene, pentane or pentene. It can be further purified by fractional crystn by partial freezing, and stored over sodium wire or molecular sieves Linde type 4A. [Stokes and French J Chem Soc, Faraday Trans 1 76 537 1980.]... 

Many 3-substituted indoles have also been prepared with the use of a-alkyl or a-aryl-p-keto sulfides. Thus indolization of aniline 5 with 3-methylthio-2-butanone 27 furnished indolenine 28, presumably via the same mechanism discussed earlier. The indolenine 28 was relatively unstable and reduced to the indole 29 without purification. Tetrahydrocarbazole 32 was prepared in 58% overall yield. Smith et al. made excellent use of the Gassman process in the total synthesis of (-i-)-paspalicine and (+)-paspalinine. ... 

Methyl-2-butanone, purchased from Eastman Organic Chemicals, was used without purification. In general, commercially available ketones may be used without further purification. 

The two established Hnls, those from L. usitatissimum and P. amygdalus, have found biocatalytic applications for the production of (i )-cyanohydrins. The former of these Hnls is the least widely applied, the natural substrates being acetone cyanohydrin or (i )-2-butanone cyanohydrin (Table 1) [28]. Although an improved procedure for the purification of this enzyme has been reported [27] it is still only available in limited quantities (from 100 g of seedlings approximately 350 U of enzyme are obtained). It was found that this enzyme transforms a range of aliphatic aldehyde and ketone substrates [27], the latter of which included five-membered cyclic (e.g. 2-methylcyclopentanone) and chlorinated ketone substrates. In contrast, attempts to transform substituted cyclohexanones and 3-methylcyclopentanone failed and it was even found that benzaldehyde deactivated the enzyme. 

N 12.61% (theory) (12.4% found in oily product of Warren) OB to COj minus 72.0%. The oily product puffed off at 187 after heating for 5 secs it did not explode by impact of 2kg wt at lOOcm hygroscopicity at 30 90% RH 0.40% volatility at 27° in 48 hrg 0.34% thermal stability at 82.2° KI test 1 min. Warren prepd it at PicArsn Lab hy adding in small portions and with agitation, pulverized di-methylolbucanone to cooled to ca 5 mixed acid consisting of nitric acid 25.3, sulfuric acid 59.6 water 15.1% in the ratio of 1.5 parts nitric acid per 1 part of butanone time of nitration 1 hour. Separation of crude product from acid and further purification was the same as described under 3,3"Dimethylol-2-hutanol Trinitrate... 

Chromatographic evaluation of the labelled molecules before and after purification was carried out using ITLC-SG or Whatman 3MM chromatography paper in different mobile phases, namely, 2-butanone (MEK), 0.9% NaCl, EtOH 0.01N HCl (90 10 vol./vol.) and butanokacetic acid H2O (4 1 5) [16.6]. The labelled molecules were also characterized by electrophoresis using Whatman No. 1 paper in Tris buffer (pH7.0) at 200 V, 80 mA for a period of 30 min. 

The copolymers were synthesized by radical initiated copolymerization of methacrylate monomers in butanone under inert conditions (dry nitrogen atmosphere). As initiator 2,2 -azobis-(2-methyl propionitrile) (AIBN) was employed. The copolymers obtained were used without further purification. The following example to produce the copolymer poly [methyl methacrylate-co-Zonyl TM-co-2-(methacryloyloxy)ethyl acetoacetate] (Table 1, polymer 21b) from three monomers illustrates the typical synthesis ... 

For coating the anodically oxidized and roughened aluminium sheets, dilute polymer solutions with 1% concentration in 2-butanone were applied without purification of the polymers synthesized as described above. The dry aluminium sheets were dipped in the polymer solution and kept there for 1 h. The coated samples were dried overnight and heated in an oven at 120° for 1 h. 

The purification procedures used for PMAA and PAA depend on the stereoregular forms [543]. With conventional polymers a variety of solvent/nonsolvent precipitation systems have been used for example, methanol/diethyl ether, water/hydrochloric acid, water/ butanone, ethanol/diethyl ether. Alternatively, the polymer is isolated by exhaustive dialysis, by freeze-drying [544] and by falling film crystallization [545]. 

Methyl-l-vinyloxy-3-butanone oxime reacts with acetylene to give also 2-(2-propenyl)-N-vinylpyrrole (Scheme 1.71), but 2,3-dimethyl-N-vinylpyrrole is not formed in this case. During fractionation and purification, 2-(2-propenyl)-N-vinylpyrrole readily polymerizes, which, apparently, is one of the reasons of its low yield. 

Finally, Gawley and Albright reported a C2-symmetric NHC-Cu complex 204 for the asymmetric hydrosilylation of a variety of structurally diverse ketones (Figure 13.26). This catalyst exhibited extraordinary enantio-selectivity in the reduction of challenging substrates such as 2-butanone and 3-hexanone. Even at low catalyst loading (2.0 mol%), the reactions occurred in minutes at room temperature and often did not require purification beyond catalyst and solvent removal. 

Synthesis of a graft copolymer wifli GMA. Ihe polymoization was carried out during 3h at 64 °C with a feed ratio of 23 wt% of macromer m2 in a 5 3 mixture of butanone and boizene, using baizoylperoxide (BPO) as radical initiator. After addition of CH2Q2 stirring was continued for IS min. Standard purification procedures were applied... 

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