Sumitomo steps

Sumitomo Chemical Co. (98—100) and Mitsubishi Kasei Co. (101) have patented single-step catalysts containing niobium and palladium. A Sumitomo example reports 93.5% MIBK selectivity at 41.8% acetone conversion and conditions of 160°C and 2 MPa. Other significant processes have been reported (60,102—110). 

Industrial Synthetic Improvements. One significant modification of the Stembach process is the result of work by Sumitomo chemists in 1975, in which the optical resolution—reduction sequence is replaced with a more efficient asymmetric conversion of the meso-cyc. 02Lcid (13) to the optically pure i7-lactone (17) (Fig. 3) (25). The cycloacid is reacted with the optically active dihydroxyamine [2964-48-9] (23) to quantitatively yield the chiral imide [85317-83-5] (24). Diastereoselective reduction of the pro-R-carbonyl using sodium borohydride affords the optically pure hydroxyamide [85317-84-6] (25) after recrystaUization. Acid hydrolysis of the amide then yields the desired i7-lactone (17). A similar approach uses chiral alcohols to form diastereomic half-esters stereoselectivity. These are reduced and direedy converted to i7-lactone (26). In both approaches, the desired diastereomeric half-amide or half-ester is formed in excess, thus avoiding the cosdy resolution step required in the Stembach synthesis. 

Sumitomo one-step MIBK process, 16 339 Summary report, in Investigational New Drug Applications, 18 693 Summer flounder aquaculture, 3 189... 

Molten-Iron Pure Gas (MIP) and Klockner Molten Iron Processes. This concept is being developed in a joint effort by Sumitomo Metal (Japan) and Klockner (Germany). Coal is gasified with oxygen in a lop- or bottom-blown liquid iron bath. The process accomplishes desulfurization ami particulate removal in one step. 

Scientists at Sumitomo developed this approach for the production of chiral insecticides [35, 61]. As discussed above, this approach involves several separate steps, an inversion replacing the racemisation that is normally necessary subsequent to a kinetic resolution. The advantage of this approach is that after the kinetic resolution no separation is necessary, since the reaction mixture is sub-... 

The first commercial applicahon, made possible by an agreement between EniChem and Sumitomo, went on-stream in 2003 in Japan, within the context of an integrated process for the produchon of e-caprolactam by a new salt-free technology (ca GOOOOta ). Actually, besides the ammoximation step, no major byproduct is produced even in the gas-phase rearrangement carried out on silicalite-1 as the catalyst. On the whole, the ammonium sulfate is no longer a burden and the gaseous emissions too are drashcally reduced. 

Not only strong acid sites but also relatively weak acid sites could be utilized in the development of improved industrial processes. One of the most significative examples is the new Sumitomo process for caprolactam manufacture, which combines a first step of ammoximation (originally developed by the Eni group [241-243]) with a second step of Beckmann rearrangement based on the use of silicalite-1 (Eigure 2.32). 

The conventional process (Figure 2.32a) involves the reaction of cyclohexanone tvith hydroxylamine sulfate (or another salt), producing cyclohexanone oxime that is subjected to the Beckmann rearrangement in the presence of stoichiometric amounts of sulfuric acid or oleum. The overall process generates about 4.5 kg of ammonium sulfate per kg of caprolactam, divided roughly equally over the two steps. The Sumitomo process (Figure 2.32b) instead produces virtually no waste and allows caprolactam to be obtained in >98% yield (based on cyclohexanone 93% based on FI2O2). 

The Sumitomo PO-only process consists of the following steps [5] (Scheme 6.4) ... 

SYNSUP-MB is a heuristic program developed particularly for industrial application by M. Bersohn of Toronto University in cooperation with Sumitomo Chemical Co. [114]. It includes a database with 2500 reactions and allows very fast automated simulation of reactions and 22,000 reactions per hour with moderately complex target molecules including multiple stereocenters. Though the user may define constraints on reaction routes, like the maximum number of reaction steps, the search is conducted without any user interaction. 

In recent years heteropolycompounds have been studied for the oxidation of propane to acrylic acid and of isobutane to methacrylie aeid. Rohm Haas Company was the first in 1981 to claim the one-step oxidation of isobutane to methacrolein and methacrylie acid (55). Even though no reference is made to heteropolycompounds, the claimed catalyst compositions correspond to Keggin-type structures. In the patents later issued by Sumitomo (56,57) an important role was claimed to be played by vanadium (in an anionic position), by cesium (in a cationic position), as well as by an excess of phosphorus with respect to the stoichiometric composition. These catalysts gave selectivities to methacrylie acid plus methacrolein close to 70 %, with isobutane conversions in the 10 to 13 % range. Besides carbon oxides, acetic acid was the main by-product. 

More than 44 million Americans live or work near places that pose risks from the storage or use of dangerous industrial chemicals.154 The cost of accidents may be more than just a monetary one to the company. A fire and explosion occurred on July 4, 1993, in a Sumitomo Chemical plant in Niihama, Japan, that made over half of all the epoxy-encapsulation resin for semiconductor chips used in the entire world. Cutting off the supply would have been a serious inconvenience to the customers. The company took the unusual step of letting other companies use its technology until it could rebuild its own plant, so that a supply crisis never developed. The company still supplied 50% of the world s requirements for that resin in 1999.155... 

Remark. Several companies have designed techniques derived from the foregoing processes, some of them leading to industrial development These include isoprene manufacture from isobutene and formaldehyde in a single step (British Hydrocarbon Chemical, Japan Institute of Physical and Chemical Research, Marathon, Sun Oil, Tokyo Institute ofTechnology), and the replacement of formaldehyde by methanol and oxygen or by methylether (Idemitsu Petrochemical, Sumitomo etc.). 

Figure 1.15 Process flow diagram for the oxidation of propylene with cumene hydroperoxide as the oxidizing agent and titanium-containing mesoporous material as the heterogeneous catalyst (Sumitomo process). The process involves the following steps (1) A process for oxidation of cumene with air to obtain CMHP, (2) a process for epox-idation of propylene in the presence of a catalyst whereby o,a-dimethyl benzyl-alcohol CMA) is concomitantly obtained from CMHP, (3) a process for the hydrogenation of CMA with H2 i n the presence of a catalyst to obtain cumene, (4) a process for purification of the cumene, followed by recycle of cumene to the oxidation process, and (5) a process for the purification of PO. Adapted from Ref. (271), with permission from Wiley-VCH.

Thirty years after the invention of ENI s TS-1, new environmentally friendly processes have been commercialized for the epoxidation of propylene and the ammoximation of cyclohexanone that have no major by-products or coproducts. The BASF-Dow and Degussa-Uhde processes claim to be environmentally friendly, have low capital investment costs, and have no significant quantities of by-products when compared to either the chlorohydrin or the PO with styrene monomer processes. The Sumitomo PO process is also beneficial for the environment, because it needs only a cumene-to-cumene hydroperoxide reactivation process step. 

Applications to Diazepam Synthesis. The Sumitomo process for diazepam is depicted below (11). According to some reports, this is a major route by which diazepam (Valium), a widely-prescribed anti-anxiety drug, is prepared on an industrial scale. I have highlighted three reactions in the Sumitomo synthesis. These reactions involve toxic or corrosive reagents which would best be avoided if pollution control is an objective. It is worth noting that almost all of the other publish pathways for the synthesis of diazepam involve Friedel Crafts reactions in the key carbon-carbon bond forming step. 

Rexene Co. and Philips Petroleum Co. first developed the bulk polymerization process with the first-generation TiCU catalyst [8,11,70]. It was then commercialized by Dart Industries in 1964. The reactor feed contains 10-30% propylene in the liquid phase. A mixture of hexane and isopropanol was employed for the removal of catalyst residue as well as the amorphous polypropylene. The process step of removing residual catalyst was later eliminated after the high-efficiency catalyst was adopted, constituting the so-called liquid pool process. Subsequently, Philips and Sumitomo companies further developed the liquid-phase polymerization process. This process enhances the reaction rate, catalyst efficiency, monomer conversion, and therefore results in high productivity. It also eliminates the need for solvent recovery and reduces environmental pollution. However, the process is somewhat complicated by the unreacted monomer, which has to be first vaporized and then liquefied before it is reused. The reaction vessel must be designed to operate under high pressures. In most cases, this process employs autoclaves for batch operation and tubular reactors for continuous operation. 

The synthesis of cllastatin constitutes one of the first enantioselective syntheses on an Industrial scale. In 1966, H. NozakI and R. Noyorl Investigated the enantioselective [2 -I-1 ]-cycloaddition of diazo-acetic esters to olefins. From this, Sumitomo developed industrial processes for the preparation of pyrethroids and cilastatin. In the key step, ethyl diazoacetate is decomposed in presence of isobutene at a dimeric, enantio-merically pure copper complex. The resulting ethyl di-methylcyclopropanecarboxyl-ate has an optical purity of 92% ee. 

In one of their patents (13WO018928), Sumitomo chemists described the preparation of S-SFs-benzimidazole 70 and its use as an active pest-control agent. In their method, SFs-nitroaniHne 60, obtained in two steps from 4-SFs-anihne (11) by N-acetylation and subsequent nitration, was first converted into JV-methyl nitroaniline 71, the nitro group of which was then reduced to amino and coupled with 3-chloropyridine-2-carboxyUc acid to give amide 72. One-pot nucleophihc substitution of chlorine in 72 with sodium ethanethiolate and further condensation furnished 2-substituted 5-SFs-benzimidazole 73, the sulfide function of which was later oxidized to sulfone using 3-chloroperoxyhenzoic acid (MCPBA), thus providing the desired insecticide 70 (Scheme 18). 

The rearrangement step is most efficiently performed by the original solid catalyst based on Si/Al zeolite and coded as ZSM-5, discovered by the research team of Sumitomo Co. (Scheme 1.20c) [17, 18]. It catalyzes the rearrangement to caprolactame with 95 % selectivity and 100 % yield, without side products. 

A noninteractive approach has been built at the Sumitomo Chemical Company for the SYNSUP program in which 2500 reactions are coded. For this purpose several limiting instructions are necessary to prune the synthesis tree. The user may give several constraints on the number of steps... 

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