Methyl pyrrolidone-5 -carboxylate

Substances related to MSG and purine 5 -ribonucleotides include peptides, amino acids (e.g. cysteine, homocysteine, cysteine S-sulfonic acid, aspartic acid, a-amino adipic acid, a-methyl glutamic acid, tricholomic acid, ibotenic acid), pyrrolidone carboxylic acid, 3-methyl thiopropyl amine, and others [2, 10], They are of less commercial interest than MSG, IMP, and GMP. Chemical structures of some of these substances are depicted in Fig. 3.53. Relative umami effects of some are shown in Tab. 3.49. Tricholomic acid and ibotenic acid have been found in the mushrooms Tricholoma muscarium and Amanita stroboliformis, respectively. 

In addition to polymer latexes, inorganic suspensions may also be formed in CO2. (10) Block copolymers have been shown by turbidimetry to stabilize 1 pm hydrophilic silica dispersions in CO2, with stability decreasing in the order PS-Z)-PFOA > poly(methyl methacrylate-co-hydroxyethyl methacrylate)-g-PFPE > poly(dimethyl-siloxane)-g-pyrrolidone carboxylic acid (PDMS-g-PCA) (MW 8500 g/mol, 2 PCA groups). The decrease in stability with decreasing CO2 density was sharper for higher molecular weight C02-philic segments, as expected based on the nature of polymer chain collapse. 

Polyimide Siloxane (SiPI). Into a 500 cc 3 neck round bottomed flask equipped with a mechanical stirrer and nitrogen bypass is placed 54.00 gms (0.17 moles) of 3,3 ,4,4 -benzophenonetetra-carboxylic dianhydride dissolved in 250 cc of sieve dried N-methyl pyrrolidone (B J). To the stirred solution is added 23.22 gms (0.12 moles) of methylene dlanillne followed by 12.6 gms (0.05 moles) of bis-1,3-gamma aminopropyltetramethyl dlsiloxane. The viscous solution is allowed to stir at room temperature for 24 hours. 

ETHYLENE CARBOXYLIC ACID (79-10-7) Forms explosive mixture with air (flash point 124°F/51°C). Light, heat, or peroxides can cause explosive polymerization. Incompatible with strong acids, alkalis, ammonia, amines, isocyanates, alkylene oxides, epichlorohydrin, oxidizers, toluenediamine, pyridine, methyl pyridine, w-methyl pyrrolidone, 2-methyl-6-ethyl aniline, aniline, ethylene diamine, ethyleneimine, 2-aminoethanol. Severely corrodes carbon steel and iron attacks other metals. Flow or agitation of substance may generate electrostatic charges due to low conductivity. The uninhibited vapors may form polymers in plug vents, confined spaces, or flame arresters of storage tanks. 

The positive electrode is produced as follows the LiCo02 powder of the positive active material and carhon black conducting agent are mixed with an N-methyl pyrrolidone (NMP) solution of PVDF binder to make a paste of appropriate viscosity. A mixture of water and carboxyl methylcellulose (CMC), with styrene butadiene rubber (SBR, used as a binding agent), is also used for making such paste. 

The reactivity of the methylene group adjacent to the lactam group affords the possibility of a Claisen condensation. Thus, treatment of 2-pyrrolidone or 2-piperidone with ethyl oxalate leads to the J -pyrroline-carboxylic (70) and, d -piperideine-2-carboxylic acids (71), respectively. N-methyl lactams furnish N-methyl derivatives (72,73) (Scheme 3). 

In a more recent study using dedicated multimode microwave reactors for chemical synthesis, which enable temperature and power control, it was demonstrated that microwave irradiation could be effectively employed to couple aromatic carboxylic acids to polystyrene Wang resin [25], if the symmetrical anhydride procedure was used, and not the three-component O-acylisourea activation method [19]. Almost quantitative loading was achieved in l-methyl-2-pyrrolidone (NMP) at 200 °C within 10 min under... 

R,5S)-(-)-6,6-Dimethyl-3-oxabicyclo[3.1,0]hexan-2-one. Highly tnantioselective Intramolecular Cyclopropanation Catalyzed by Dirhodium(ll) Tetrakis[methyl 2-pyrrolidone-5(R)-carboxylate],... 

However, morpholine-4-carboxylic acid 2-hydroxy-1-methyl-ethyl ester is formed by the reaction of PC and the substrate morpholine in an undesired side reaction. By use of 1.4-dioxane or the pyrrolidones as mediator s3 about 30 to 45% of the morphoUne is consumed by this side reaction. The by-product is contained in the PC phase and can not be extracted to the non-polar product phase. The selectivity to the desired amines is lowered, because of the consiunption of the morphoUne. Thus, PC has to be substituted by another polar solvent (e.g. water, methanol or ethylene glycol) in future experiments. The lactates react with the morphoUne, too resulting in the corresponding amide. Overall, the hydroaminomethylation in the TMS systems PC/dodecane/lactate results in a conversion of 1-octene of about 80%, but in selectivities to the amines of only 50 to 60%. 

The amidic group in methyl A -acetyl-p-aminobenzoate was reduced preferentially to an ester group with borane in tetrahydrofuran (1.5-1.8 mol per mol of the amide), giving 66% yield of methyl p-A -ethylaminobenzoate. Similarly l-benzyl-3-methoxycarbonyl-5-pyrrolidone afforded methyl l-ben2yl-3-pyr-rolidinecarboxylate in 54% yield and l,2-diethyl-5-ethoxycarbonyl-3-pyra-zolidone gave ethyl l,2-diethylpyrazolidine-3-carboxylate in 60% yield. 

Successive addition of monomers to the end of macromolecular initiator is the usual technique for the synthesis of tailored blockcopolymers. Anionic polymerization of pivalolactone, a-pyrrolidone— and the NCA of T-methyl-D-glutamate -2 was started from the end group of a prepolymer consisting carboxylate group or acyl lactam group or amino group. Living polymer of C-capro-lactone was expected to be formed by the initiated polymerization from polymer carbanion under kinetic controlled condition. 

Bromo-ll//-pyrido[2,l-b]quinazolin-ll-one and its 8-methyl and 8-isopropyl derivatives (127, R = Br, R1 = H, Me, iPr) were treated with carbon monoxide and nickel carbonyl in wet dimethylformamide in the presence of calcium hydroxyde to yield 2-carboxylic acid derivatives (127, R = COOH, R1 = H, Me, iPr). 2-Bromo-8-isopropyl-ll//-pyrido[2,l-b]-quinazolin-ll-one (127, R = Br, R1 = iPr) was reacted with copper(I) cyanide in iV-methyl-2-pyrrolidone at 180°C for 10 h, then with ferric chloride hexahydrate in diluted hydrochloric acid at 90°C for 30 min to give the 2-cyano derivative (127, R = CN, R1 = iPr) (85CP1189509). 

Chiral rhodium(II) carboxamides are exceptional catalysts for highly enantio-selective intermolecular cyclopropenation reactions (50). With ethyl diazoacetate and a series of alkynes, use of dirhodium(II) tetrakis[methyl 2-pyrrolidone-5-(R)-carboxylate], Rh2(5R-MEPY)4, in catalytic amounts ( 1.0 mol %) results in the formation of ethyl eyelopropene-3-earboxylates (eq 4) with enantiomeric excesses... 

As in benzenoid chemistry, some nucleophilic displacement reactions can be copper catalyzed. Illustrative of these reactions is the displacement of bromide from 3-bromothiophene-2-carboxylic acid and 3-bromothiophene-4-carboxylic acid by active methylene compounds (e.g., AcCH2C02Et) in the presence of copper and sodium ethoxide (Scheme 136). Analogously, 2-methoxythiophene can be prepared in 83% yield by refluxing 2-bromothiophene in methanol containing excess sodium methoxide, along with copper(I) bromide as catalyst. For the analogous preparation of 3-methoxythiophene, addition of a polar cosolvent (e.g., l-methyl-2-pyrrolidone) is beneficial. In the case of halothiophenes, an SrnI mechanism is involved. 

R,5S)-(-)-6,6-DIMETH YL-3-OXABICYCLO[3.1. OJHEXAN-2-ONE. HIGHLY ENANTIOSELECTIVE INTRAMOLECULAR CYCLOPROPANATION CATALYZED BY DIRHODIUM(II) TETRAKIS[METHYL 2-PYRROLIDONE-5(R)-CARBOXYLATE]... 

B. (+)-Dirhodium(ll) tetral[Pg.14]

When the reaction is followed by HPLC using a p-Bondapak-CN column with 2% acetonitrile in methanol as the eluent, two bands are observed initially a broad band eluting with the solvent front [chlorobenzene and excess methyl 2-pyrrolidone-5(R)-carboxylate] and a second band at 1.6 min when the flow rate is 1.5 mlVmin (rhodium(ll) acetate]. As the reaction progresses, the rhodium(ll) acetate band diminishes and is replaced by several bands with longer retention volumes until one major band, in addition to that for chlorobenzene and ligand, is observed at about 4 min. Only minor impurities elute at intermediate times. A brown-black material, insoluble in all common solvents, is observed in some preparations. The origin of this material is unknown, but its presence decreases product yield by 25%. 

Unreacted methyl 2-pyrrolidone-5(R)-carboxylate may be reisolated by distillation (70% recovery) without loss of optical purity. 

This is the first detailed procedure for the synthesis of a chiral dirhodium(ll) carboxamide catalyst and its application to intramolecular cyclopropanation. The preparation of the ligand, methyl 2-pyrrolidone-5(R)-carboxylate, is adapted from the procedure of Ackermann, Matthes, and Tamm.2 The method for ligand displacement from dirhodium(ll) tetraacetate is an extension of that reported for the synthesis of dirhodium(ll) tetraacetamide.6 The title compound, (1 R,5S)-(-)-6,6-dimethyl-3-oxabicyclo[3.1.0]hexan-2-one, is a synthetic precursor to (1 R,3S)-(+)-cis-chrysanthemic acid.5... 

Dirhodium(ll) tetrakis[methyl 2-pyrrolidone-5(R)-carboxylate Rh2(5R-MEPY)4t Rhodium, tetrakis[ x-(methyl 5-oxo-L-prolinato-N1 Os)]di-, (Rh-Rh) (12) (1324-35-65-5) Thionyl chloride (8,9) (7719-09-7)... 

Methyl 2-pyrrolidone-5(R)-carboxylate D-Proline, 5-oxo-, methyl ester (10) (64700-65-8)... 

This collection begins with a series of three procedures illustrating important new methods for preparation of enantiomerically pure substances via asymmetric catalysis. The preparation of 3-[(1S)-1,2-DIHYDROXYETHYL]-1,5-DIHYDRO-3H-2.4-BENZODIOXEPINE describes, in detail, the use of dihydroquinidine 9-0-(9 -phenanthryl) ether as a chiral ligand in the asymmetric dihydroxylation reaction which is broadly applicable for the preparation of chiral dlols from monosubstituted olefins. The product, an acetal of (S)-glyceralcfehyde, is itself a potentially valuable synthetic intermediate. The assembly of a chiral rhodium catalyst from methyl 2-pyrrolidone 5(R)-carboxylate and its use in the intramolecular asymmetric cyclopropanation of an allyl diazoacetate is illustrated in the preparation of (1R.5S)-()-6,6-DIMETHYL-3-OXABICYCLO[3.1. OJHEXAN-2-ONE. Another important general method for asymmetric synthesis involves the desymmetrization of bifunctional meso compounds as is described for the enantioselective enzymatic hydrolysis of cis-3,5-diacetoxycyclopentene to (1R,4S)-(+)-4-HYDROXY-2-CYCLOPENTENYL ACETATE. This intermediate is especially valuable as a precursor of both antipodes (4R) (+)- and (4S)-(-)-tert-BUTYLDIMETHYLSILOXY-2-CYCLOPENTEN-1-ONE, important intermediates in the synthesis of enantiomerically pure prostanoid derivatives and other classes of natural substances, whose preparation is detailed in accompanying procedures. 

Semicorrinato)copper catalysts have also been used for intramolecular cyclopropanation reactions of alkenyl diazo ketones (eq 9 and eq 10). In this case the (semicorrinato)copper catalyst derived from complex (5) proved to be superior to related methylene-bis(oxazoline)copper complexes. Interestingly, analogous allyl diazoacetates react with markedly lower enantioselectivity under these conditions, in contrast to the results obtained with chiral Rh complexes which are excellent catalysts for intramolecular cyclopropanations of allyl diazoacetates but give poor enantioselectivities with alkenyl diazo ketones (see Dirhodium(II) Tetrakis(methyl 2-pyrrolidone-5(S -carboxylate ) Moderate enantioselectivities in the reactions... 

Dirhodium(II) Tetrakis(methyl 2-pyrrolidone-5(S)-carboxylate), 320 C24H38O3... 

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