New route

The synthesis of MMDA in Pihkal is one of the longest and most tedious in the book. If one is going the route via myristicin, the Sisifos work of isolating the tiny amount of essential oil present in nutmeg, followed by fractional distillation to purify the myristicin fraction is also added to the labor of the poor chemist. Therefore I propose a new route to this "essential amphetamine". 

A conceptually surprising and new route to prostaglandins was found and evaluated by C.R. Johnson in 1988. It involves the simple idea to add alkenylcopper reagents stereo-selectively to a protected chiral 4,5-dihydroxy-2-cyclopenten-l-one and to complete the synthesis of the trisubstituted cyclopentanone by stereoselective allylation of the resulting enolate. 

This process comprises passing synthesis gas over 5% rhodium on Si02 at 300°C and 2.0 MPa (20 atm). Principal coproducts are acetaldehyde, 24% acetic acid, 20% and ethanol, 16%. Although interest in new routes to acetaldehyde has fallen as a result of the reduced demand for this chemical, one possible new route to both acetaldehyde and ethanol is the reductive carbonylation of methanol (85). 

H. S. Bloch, "A New Route to Linear Alkylbenzenes," Symposium on / -Paraffins, Institute of Chemical Engineers (NW Branch). 

Enzymatic hydrolysis of A/-acylamino acids by amino acylase and amino acid esters by Hpase or carboxy esterase (70) is one kind of kinetic resolution. Kinetic resolution is found in chemical synthesis such as by epoxidation of racemic allyl alcohol and asymmetric hydrogenation (71). New routes for amino acid manufacturing are anticipated. 

Catalytic reactions at somewhat lower temperatures also produce ethylene and other olefins. When coupled with a methane process to methyl chloride, this reaction results ia a new route to the light hydrocarbons that is of considerable interest. 

Aryl lead tncarboxylates have been shown to be intermediates in two new routes to phenols, and to have considerable potential as reagents for the C-arylation of carbon acids which are more acidic than diethyl malonate. A... 

There are two further processes. Silicon-based ceramics can be fabricated by sintering or by hot-pressing. But a new route, reaetion bonding (Fig. 19.6), is cheaper and gives good precision. If pure silicon powder is heated in nitrogen gas, or a mixture of silicon and carbon powders is sintered together, then the reactions... 

The first methacrylic esters were prepared by dehydration of hydroxyisobutyric esters, prohibitively expensive starting points for commercial synthesis. In 1932 J. W. C. Crawford discovered a new route to the monomer using cheap and readily available chemicals—acetone, hydrocyanic acid, methanol and sulphuric acid— and it is his process which has been used, with minor modifications, throughout the world. Sheet poly(methyl methacrylate) became prominent during World War II for aircraft glazing, a use predicted by Hill in his early patents, and since then has found other applications in many fields. 

Another method of simulating chemical reactions is to separate the reaction and particle displacement steps. This kind of algorithm has been considered in Refs. 90, 153-156. In particular. Smith and Triska [153] have initiated a new route to simulate chemical equilibria in bulk systems. Their method, being in fact a generalization of the Gibbs ensemble Monte Carlo technique [157], has also been used to study chemical reactions at solid surfaces [90]. However, due to space limitations of the chapter, we have decided not to present these results. 

A new route to nitnle oxides based on the reacdon of primary alkyl bromides v/ith NaNOj n the presence of acedc acid, is also reported fEq. 6.35. This reacdon is used for the direct... 

Dimethyl carbonate (DMC) is a colorless liquid with a pleasant odor. It is soluble in most organic solvents but insoluble in water. The classical synthesis of DMC is the reaction of methanol with phosgene. Because phosgene is toxic, a non-phosgene-route may be preferred. The new route reacts methanol with urea over a tin catalyst. However, the yield is low. Using electron donor solvents such as trimethylene glycol dimethyl ether and continually distilling off the product increases the yield. ... 

A new route to ethylene glycol from ethylene oxide via the intermediate formation of ethylene carbonate has recently been developed by Texaco. Ethylene carbonate may be formed by the reaction of carbon monoxide, ethylene oxide, and oxygen. Alternatively, it could be obtained by the reaction of phosgene and methanol. 

BASF is operating a semicommercial plant for the production of adipic acid via this route.A new route to adipic acid occurs via a sequential carbonylation, isomerization, hydroformylation reactions.The following illustrates these steps ... 

Rearrangement of methyl 4,6-0-benzylidene-3-deoxy-3-phenylazo-aldohexopyranosides with alkali provides a new route to hexosid-3-uloses (18). 

The well-known reaction leading to ring expansion of cyclic ketones has been applied to derivatives of oxo sugars in an attempt to develop a new route to novel deoxy sugars. By treatment with diazomethane both a five-membered (42) and a six-membered (26) sugar ring have been expanded by insertion of a methylene group. 

A new route to 2//-thiopyrans has been found in the cyclocondensation of thioenolates with a./J-unsaturated carbonyl compounds. The starting sulfur component can be methyl thiol-thione-ethanoate (90BSF446) or a /3-thienol-aldehyde (90ZC247) as shown by Eqs. (1) and (2), respectively. 

Inoue, S., Sugiura, S., Kakoi, H., and Goto, T. (1969). Cypridina bioluminescence. VIA new route for the synthesis of Cypridina luciferin and its analogs. Tetrahedron Lett., pp. 1609-1610. 

This new lower price changed the comparative economic advantages of some of the newer plastics and led to a search for new uses of acrylonitrile and its polymers and copolymers. A new route to Dacron was developed by du Pont using this lower priced acrylonitrile and the use of acrylic fabrics grew rapidly. There was also an increase in uses of ABS and acrylonitrile production capacity. 

The new knowledge and understanding of radical processes has resulted in new polymer structures and in new routes to established materials many with commercial significance. For example, radical polymerization is now used in the production of block copolymers, narrow polydispersity homopolymers, and other materials of controlled architecture that were previously available only by more demanding routes. These commercial developments have added to the resurgence of studies on radical polymerization. 

The first type of polycarbosilane synthesized by using ADMET methodology was a poly[carbo(dimethyl)silane].14c Linear poly(carbosilanes) are an important class of silicon-containing polymers due to their thermal, electronic, and optical properties.41 They are also ceramic precursors to silicon carbide after pyrolysis. ADMET opens up a new route to synthesize poly(carbosilanes), one that avoids many of the limitations found in earlier synthetic methods.41... 

Developments in the synthesis and characterization of stable silylenes (RiSi ) open a new route for the generation of silyl radicals. For example, dialkylsilylene 2 is monomeric and stable at 0 °C, whereas N-heterocyclic silylene 3 is stable at room temperature under anaerobic conditions. The reactions of silylene 3 with a variety of free radicals have been studied by product characterization, EPR spectroscopy, and DFT calculations (Reaction 3). EPR studies have shown the formation of several radical adducts 4, which represent a new type of neutral silyl radicals stabilized by delocalization. The products obtained by addition of 2,2,6,6-tetramethyl-l-piperidinyloxy (TEMPO) to silylenes 2 and 3 has been studied in some detail. ... 

This new route of access has required new approaches. Rather than sewing together a collection of review articles, a framework has had to be designed that reflects the creative potential of the science and is hoped to stimulate its further development by identifying areas of research that are most likely to be fruitful. 

NEW ROUTE TO ENGINEERING PLASTICS PRODUCED FROM WASTE CARPETS... 

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