Methylpropyl carbonate

Following the initial work by Smart et al., similar efforts were reported based on various binary and ternary compositions, such as EC/DMC/EMC (1 1 1) 503,505,509 eC/DMC/DEC (2 2 l),so5 EC/EMC (1 3), ° EC/DMC/methylpropyl carbonate (MFC) and EC/DMC/isopropyl carbonate (iPC) at a series of varying compositions.Unfortunately, below —30 °C the above compositions still failed to function well. ... 

The Ugi group has designed a new class of convertible isocyanides, namely alkyl 2-isocyano-2-methylpropyl carbonates [7], prepared from commercially available 4,4-dimethyl-2-oxazoline. The Ugi-4CR of 11 afforded the expected products 12, which were converted into N-acyl a-amino acid esters 13 and N-acyl a-amino acids by in situ hydrolysis (Scheme 2.5) [7]. 

In 1999, Ube Industries, Ltd. discovered carbonates containing branched alkyl groups, such as methyl 1-methylpropyl carbonate (155) and methyl sec- >vXy carbonate (156) [149]. 

Based on the concepts discussed in Section 2.3 above, it is clear that to optimize the electrolyte solution for chemical and electrochemical stability, and for conductivity, a mixed solvent approach is required. Eor chemical and electrochemical stability, clearly solvents containing EC, EMC, DMC and, to a lesser extent, DEC are required other useful asymmetric carbonate-based solvents have also been studied, e.g. ethylpropyl and isopropylmethyl carbonates [45], methylpropyl carbonate [83] and 2-methoxyethyl (methyl) carbonate [84], but the key solvents for electrochemical stability are EC, EMC and DMC. The superiority of a 1 1 1 (by volume) mixture of EC EMC DMC with 1 nrtol dm" LiPFe was reported in [85], and 1 1 1 (by volume) of EC EMC DEC with 1 mol-dm LiPFe was reported in [86]. Figure 10 summarizes the conductivities of various electrol 4es in 1 1 1 mixtures of EC EMC DMC and EC DEC DMC. At 0°C, the conductivities of 1 mol-dm LiPFe solutions are ITO S-cm" wltile those for LiMe and LiBETT are aU 0.5TO S-cm The low temperature cycling behavior of Li-ion cells in LiPFg solutions is superior in the EC EMC DMC electrolyte (e.g., compare Figures 11 and 12). 

The C4H9 alkyl groups may be derived either from the unbranched carbon skele ton of butane or from the branched carbon skeleton of isobutane Those derived from butane are the butyl (n butyl) group and the 1 methylpropyl (sec butyl) group... 

Those derived from isobutane are the 2 methylpropyl (isobutyl) group and the 1 1 dimethylethyl (tert butyl) group Isobutyl is a primary alkyl group because its poten tial point of attachment is to a primary carbon tert Butyl is a tertiary alkyl group because Its potential point of attachment is to a tertiary carbon... 

CN carbonic acid l,2-ethanediylbis[(2,6-dioxo-4,l-piperazinediyl)methylene] bis(2-methylpropyl) ester... 

CASRN 314-40-9 molecular formula C9Hi3BrN202 FW 261.12 Soil Metabolites tentatively identified in soil were 5-bromo-3-(3-hydroxy-l-methylpropyl)-6-methyluracil, 5-bromo-3-5ec-butyl-6-hydroxymethyluracil, 5-bromo-3-(2-hydroxy-l-methylprop-yl)-6-methyluracil, and carbon dioxide. The presence of uracil products suggests that bromacil was degraded via hydroxylation of the side chain alkyl groups. In the laboratory, 25.3% of C-bromacil degraded in soil to carbon dioxide after 9 wk but mineralization in the field was not observed. The half-life of bromacil in a silt loam was 5-6 months (Gardiner et al, 1969). 

Tirey et al. (1993) evaluated the degradation of phorate at three different temperatures. When oxidized at temperatures of 200, 250, and 275 °C, the following reaction products were identified by GC/MS ethanol, ethanethiol, methyl mercaptan, 1,2,4-trithiolane, 1,1-thiobisethane, 1,1 -(methylenebis(thio))bisethane, 1,3,5-trithiane, 0,0-diethyl-5-pentenyl phosphorodithioic acid, ethylthioacetic acid, diethyl disulfide, 2,2 -dithiobisethanol, ethyl-(1-methylpropyl) disulfide, sulfur dioxide, carbon monoxide, carbon dioxide, sulfuric acid, and phosphine. 

Dobutamine Dobutamine, ( ) 4-[2(4 -hydroxyphenyl)-l-methylpropyl]-3,4-dihydrox-yphenylethylamine (11.1.31), differs significantly from all of the presented drugs in terms of structure, the main difference being the absence of a hydroxyl group at the )3-carbon atom of the phenylethylamine moiety of classic sympathomimetics. The second considerable difference from the examined drugs is the presence of p-hydroxyphenyl-iso-buty-lamine group as a terminal amine substituent. 

Substituted 3,6-dialkoxy-2,5-dihydropyrazines are regioselectively metalated by strong alkyl-lithium bases, such as butyllithium, (l-methylpropyl)lithium, fcrf-butyllithium, or lithium diiso-propylamide, at the less substituted carbon atom (C5). Metalation proceeds at low temperatures (in general, below — 70 C) in THF as solvent. Electrophiles suitable for alkylation of the lithiated derivatives include alkyl iodides, bromides and chlorides, as well as alkyl methanesulfonates, 4-methylbenzenesulfonates and trifluoromethanesulfonates. The electrophile adds trans to the substituent at C2 in a highly stereoselective fashion, with typical diastereomeric excesses of greater than 90% (syn addition has been reported in only one case where a-methylphenyl alanine was used as chiral auxiliary and an alkyl trifluoromethanesulfonate as electrophile18). 

The xylene phase is removed and the aqueous phase is made alkaline with sodium hydroxide. The free base obtained is extracted with ether and the ethereal extracts are dried over anhydrous potassium carbonate and concentrated to dryness. The residue is distilled in vacuo. 3-Cyano-10-(3-dimethylamino-2-methylpropyl)phenthiazine (8.5 g), BP 180° to 205°C/0.9 mm Hg, is thus obtained. The acid maleate prepared in and recrystallized from ethanol melts at 204° to 205°C. 

Scheme 16 The U-4CR with 2-Isocyano-2-methylpropyl Methyl Carbonate ...

An aldehyde (8 mmol) and a primary amine (8 mmol) were stirred in MeOH (16 mL) at 25 °C for 2h. 2-Isocyano-2-methylpropyl methyl carbonate (53 8 mmol) and a carboxylic acid (8 mmol) were then added and the mixture was stirred for 24 h. The solvent was removed, and the product 54 was isolated by flash chromatography (silica gel, hexane/EtOAc 3 1) as a mixture of rotamers. 

When 2-hydroxy-3,5-diphenylpyrazine 1-oxide was heated under reflux with an excess of acetic anhydride, a crystalline triacetoxy compound was obtained which was thought to have an open chain structure [AcO-CH=CPh-N=CPh-C(OAc)=N-OAc], but when the 2-hydroxypyrazine-l-oxide was boiled with a mixture of acetic anhydride and acetic acid, 2,6-diacetoxy-3,5-diphenylpyrazine was obtained (873) which was hydrolyzed by potassium hydrogen carbonate in methanol to 2,6-dihydroxy-3,5-diphenylpyrazine (873). 2-Hydroxy-5-methyl-3-phenylpyrazine 1-oxide behaved differently and when refluxed with acetic anhydride gave 5-acetoxymethyl-2-hydroxy-3-phenylpyrazine (100) and 2-hydroxy-3-methyl-5-phenylpyrazine 1-oxide similarly gave 3-acetoxymethyl-2-hydroxy-5-phenylpyrazine (873). When 2- l-hydroxy-2 -methylpropyl)-5-isobutylpyrazine 1-oxide was heated with a mixture of acetic anhydride and sodium acetate on a water bath 2-(l -acetoxy-2 -methylpropyl)-5-isobutylpyrazine 1 oxide was obtained (760a). 

The resorcinols used as starting materials in the present process are either resorcinol itself (III, R=H) or a 5-alkylresorcinol (III, R=alkyl). The alkyl group may have up to twelve carbon atoms and it may be either branched or straight-chained. Examples of such alkyl groups are methyl, ethyl, propyl, sec-butyl, pentyl, 1,1-dimethylbutyl, 1,2-dimethylbutyl, l-ethyl-2-methylpropyl, isohexyl, heptyl, 1-methylhexyl, 1,2-dimethylhexyl, 1,2-dimethylheptyl, 1-methyloctyl, and 1-methylnonyl. 

CHLOROBIS (2-METHYLPROPYL)-ALUMINUM ( 1 7 7 9 - 2 5 - 5 ) [(CH3)2CHCH2]2A1C1 Pyrophoric ignites spontaneously in air (flashpoint 0°F/-18°C). Reacts with air, forming hydrogen chloride and aluminum oxide fumes. Violent, explosive reaction with water. Reacts with steam, acids, alcohols, amines, ammonium persulfate, bromine dioxide, carbon dioxide. 

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