Isopropyl compounds, structure

But this is all with the normal-propyl compound. There is a rich collection of misinformation and potential discovery that is associated with the isopropyl isomer. This structural isomer, 2,5-dimethoxyl-4-(i)-propylamphetamine is properly called DOIP for des-oxy-iso-propyl. It has been synthesized and explored in animals and, to a modest extent, in man. The synthesis has proceeded from 2,5-dimethoxyacetophenone by the addition of a methyl group to the carbonyl followed by reduction to the hydrocarbon. Aldehyde formation, nitropropene synthesis with nitroethane, and lithium aluminum hydride reduction are uneventful, providing the hydrochloride salt DOIP, which has a mp of 183-184 °C as an analytical sample. Animal tests (such as rabbit hyperthermia assays), have indicated that the isopropyl compound DOIP is less potent than the... 

Either of these two kinds of hydrogen can be replaced by an X to give a propyl compound (Fig. 2.29). The linear compound CH3 — CH2—CH2—X, in which X replaces a methyl hydrogen, is called propyl X (in the old days, w-propyl X). The branched compound CH3 — CHX—CH3, in which X replaces a hydrogen on the methylene carbon, is called isopropyl X (and sometimes 1-propyl X). Propyl compounds and isopropyl compounds are structural isomers of each other they are compounds with the same formula but different structures. 

Many carbamates have been used as protective groups. They are arranged in this chapter in order of increasing complexity of structure. The most useful compounds (not necessarily the simplest structures) are /-butyl (BOC), readily cleaved by acidic hydrolysis benzyl (Cbz or Z), cleaved by catalytic hydrogenol-ysis 2,4-dichlorobenzyl, stable to the acid-catalyzed hydrolysis of benzyl and /-butyl carbamates 2-(biphenylyl)isopropyl, cleaved more easily than /-butyl carbamate by dilute acetic acid 9-fluorenylmethyl, cleaved by /3-elimination with base isonicotinyl, cleaved by reduction with zinc in acetic acid 1-adamantyl, readily cleaved by trifluoroacetic acid and allyl, readily cleaved by Pd-catalyzed isomerization. 

A different approach leading to thianthrene derivatives starts from 0-ethyl or 0-isopropyl dithiocarbonate 394, when heated with chlorodinitrobenzene derivative 59 provided intermediate 395, the compound having all features necessary for denitrocyclization reaction to the final product 396, which was the only isolated compound (Scheme 61). Its structure was assigned by X-ray crystallography (77JOC2896). 

Methyl m-tolyl (8), ethyl m-tolyl, methyl n-butyl and methyl n-propyl sulfoxides were obtained in 100% e.e. This method was less successful when applied to methyl phenyl sulfoxide (5% e.e.) or to methyl isobutyl and methyl ethyl sulfoxides (25% e.e.). No complexes were formed between methyl o-tolyl, methyl p-tolyl, methyl 2-butyl and methyl isopropyl sulfoxides so these compounds could not be resolved using 7. A crystal structure of the 1 1 complex formed between 7 and 8 revealed that the partners were linked by OH—OS hydrogen bonds in endless zig-zag chains23. More recently, 2-chloroethyl m-tolyl sulfoxide (9) has been resolved using 724. 

Although the actual reaction mechanism of hydrosilation is not very clear, it is very well established that the important variables include the catalyst type and concentration, structure of the olefinic compound, reaction temperature and the solvent. used 1,4, J). Chloroplatinic acid (H2PtCl6 6 H20) is the most frequently used catalyst, usually in the form of a solution in isopropyl alcohol mixed with a polar solvent, such as diglyme or tetrahydrofuran S2). Other catalysts include rhodium, palladium, ruthenium, nickel and cobalt complexes as well as various organic peroxides, UV and y radiation. The efficiency of the catalyst used usually depends on many factors, including ligands on the platinum, the type and nature of the silane (or siloxane) and the olefinic compound used. For example in the chloroplatinic acid catalyzed hydrosilation of olefinic compounds, the reactivity is often observed to be proportional to the electron density on the alkene. Steric hindrance usually decreases the rate of... 

Salts with the same structure have been put forward to explain the detonations or ignitions that were observed during several accidents involving DMSO and sodium hydride, sodium isopropylate and potassium tert-butylate. However, it is known that the last-named base causes the ignition of nearly all organic compounds. 

Bis[(tris(isopropyl)cyclopentadienyl)]zinc (Zn C5(Pr1)3H2 2, 21) and bis[(tetrakis(isopropyl)cyclopentadienyl)]zinc (Zn C5(Pr1)4H 2, 22) were synthesized from the respective potassium cyclopentadienides and zinc iodide as shown in Scheme 18.50 The same slipped sandwich compounds were also isolated from zinc-reduced VC13 solutions when they were treated with these alkali metal cyclopentadienides at room temperature.51 The outcomes of these reactions suggest that zincocenes are likely intermediates in the syntheses of transition metal metallocenes, in which the metal halides have been pre-reduced with zinc. The solid-state structure of Zn G5(Pr1)4H 2 is shown in Figure 10. The sole... 

The first structurally characterized triarylzincate [Li(TMEDA)2][Zn 2,4,6-(Pr1)3G6H2 3] 59 was a byproduct of the lithiation of VC13(THF)3 with Li(2,4,6-(Pr1)3C6H2)3, in which the vanadium compound had been pre-reduced with metallic zinc.116 In the solid state, the compound consists of isolated, tetrahedrally coordinated lithium ions and trigonal-planar tris(tris(isopropyl)phenyl)zincate ions. The Zn-G bonds are equidistant (2.039(7) A), but the C-Zn-C bond angles are variable, ranging from 112.2(3)° to 125.4(3)°. 

The crystal structure of the salts [l, l"-R2-l,l"-biferrocene][Ni(mnt)2] (R = isopropyl or dineopentyl) consist of segregated chains of anions and cations. For the compound with R = isopropyl the chains are based on an arrangement of slightly trimerized anions, [Ni(mnt)2]33, with close interanionic separations, while in the case of the compound with R = dineopentyl, although the structure is still based on a similar arrangement, the anionic units are quite separated from each other. In both compounds a decrease of yT with cooling is observed, indicating dominant AF interactions [70],... 

The structure is that of an alcohol with the hydroxyl group on the second carbon atom of a three carbon chain. The compound is 2-propanol (commonly isopropyl alcohol). 

For this library, we chose to use three types of isocyanates (neutral, electron rich, and electron deficient) to demonstrate the broad utility of the urea-formation reactions. Employing the above strategy and using the split-and-pool approach, we synthesized a 27-membered urea library with purities ranging from 95 to 99%. All the compounds prepared were characterized by 1FI NMR and mass spectroscopy. Acetonitrile can also be used as a substitute for DCM, but lower yields and product purities are generally observed. Attempts to use other protic solvents, such as isopropyl and ethyl alcohol, were unsuccessful. The best results were achieved when a chlorinated solvent (DCM) was used. The structure identity of all products was confirmed by 1FI NMR and MS spectroscopy. Expected molecular ions (M + Na+) were observed for all the products, and in all cases as the base peak. The compounds and yields are listed in Appendix 3.1. 

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