Lithium n-butyl

Thus o-hydroxyphenyl-llthium cannot be obtained from o-bromophenol and lithium but, under proper conditions, o-bromophenol reacts with n-butyl-lithium to give a good yield of the lithium salt of o-hydroxyphenyl-hthium. An interesting application is to the preparation from m-bromochlorobenzene and M-butyl-lithlum of w-chlorobenzoic acid—an expensive chemical ... 

If a clear solution of n-butyl-lithium is required for any purpose, it may be decanted through a glass wool plug as detailed under 2-Phenylpyridine, Note 4. 

In a related procedure A -melhyl-o-loluidine can be A-lithiated, carboxylated and C-lithiated by sequential addition of n-butyllithium, CO2, and n-butyl-lithium[5]. The resulting dilithiated intermediate reacts with esters to give 1.2-disubstituted indoles. 

The methylhydrazone of acetophenone (112) underwent ready reaction with n-butyl-lithium giving the dianion (113) reaction with acid derivatives such acid chlorides or esters resulted in pyrazole (114) formation whereas with aldehydes, pyrazolines were obtained (76SC5). With dichloromethyleneiminium salts (115), 5-dimethylaminopyrazoles... 

The function of the trap is to condense the hexane from the n-butyl-lithium solution. The checkers used a 1-L three-necked flask fitted with a short delivery tube (a quick fit air bleed tube was used), stopper, and rubber tubing connection. The submitters used a water aspirator and a 1-L filter flask with a drying tower between. 

Polystyrene produced by free-radical polymerisation techniques is part syndio-tactic and part atactic in structure and therefore amorphous. In 1955 Natta and his co-workers reported the preparation of substantially isotactic polystyrene using aluminium alkyl-titanium halide catalyst complexes. Similar systems were also patented by Ziegler at about the same time. The use of n-butyl-lithium as a catalyst has been described. Whereas at room temperature atactic polymers are produced, polymerisation at -30°C leads to isotactic polymer, with a narrow molecular weight distribution. 

One way to generate carbanions is to combine an acidic molecule with one equivalent of a very strong base, such as n-butyl lithium (n-BuLi). For example, reaction of the alkyne shown below with n-BuLi leads to a carbanion of formula CsH, 02 , which then undergoes an Sn2 reaction with n-propyl bromide (n-PrBr),... 

Acetyl-2-Dimethylsulfamylthioxanthene A suspension of 2-dimethylsulfamylthioxanthene (12.22 grams, 0.04 mol) in 60 ml of dimethoxymethane is cooled to 0°C and 17.2 ml of a 2.91 M solution of n-butyl lithium in heptane is added slowly in a nitrogen atmosphere while the temperature is maintained below 10°C. After an additional 10 minutes of stirring, the cooling bath is removed and a solution of 2.96 grams of methyl acetate in 20 ml of di-methoxyethane is added during % hour and then the mixture is stirred at 25°C for an additional 3 hours. The reaction mixture is then treated with 60 ml of ethyl acetate and with 60 ml of a 10% aqueous ammonium chloride solution. The layers are separated and the ethyl acetate layer is washed once with water (25 ml) and then the solvent is removed by distillation. 

Co304 with an excess of n-butyl lithium results in further lithiation of the oxide particles, but with a concomitant extrusion of very finely divided transition metal from the rock salt structure. Highly lithiated iron oxide particles are pyrophoric if exposed to air [100]. 

A solution of hex-l-yne (0.3 mol) in ether (100 ml) was treated consecutively at -78 °C with a solution of n-butyl lithium (0.306 mol) in hexane and with TMSC1 (0.306 mol). The reaction mixture was brought to ambient temperature, stirred for 2h, and then quenched with ice-water. The layers were separated, and the aqueous layer was re-extracted with pentane. The combined organic extracts were washed with water and brine, and dried. Concentration and distillation gave the alkynylsilane (0.267mol, 89%), b.p. 71-73 C/36mmHg. 

The research programme into n-butyl lithium initiated, anionic polymerization started at Leeds in 1972 and involved the construction of a pilot scale, continuous stirred tank reactor. This was operated isothermally, to obtain data under a typical range of industrial operating conditions. 

A pilot scale plant, incorporating a three litre continuous stirred tank reactor, was used for an investigation into the n-butyl lithium initiated, anionic polymerization of butadiene in n-hexane solvent. The rig was capable of being operated at elevated temperatures and pressures, comparable with industrial operating conditions. 

The first example of chemically induced multiplet polarization was observed on treatment of a solution of n-butyl bromide and n-butyl lithium in hexane with a little ether to initiate reaction by depolymerizing the organometallic compound (Ward and Lawler, 1967). Polarization (E/A) of the protons on carbon atoms 1 and 2 in the 1-butene produced was observed and taken as evidence of the correctness of an earlier suggestion (Bryce-Smith, 1956) that radical intermediates are involved in this elimination. Similar observations were made in the reaction of t-butyl lithium with n-butyl bromide when both 1-butene and isobutene were found to be polarized. The observations were particularly significant because multiplet polarization could not be explained by the electron-nuclear cross-relaxation theory of CIDNP then being advanced to explain net polarization (Lawler, 1967 Bargon and Fischer, 1967). 

Studies of alkyl halide-lithium alkyl reactions have been almost wholly concerned with proton polarization. The one exception to date is an investigation of polarization in the reaction of n-butyl lithium with p-fluorobenzyl chloride giving p,p -difluorobibenzyl (A/E multi-plet) and l-fluoro-4-pentylbenzene (E/A) (Rakshys, 1970). Surprisingly H-polarization is not observed. 

The synthesis of S-phosphonothiazolin-2-one 133 started with 2-bromothiazole 129. Nucleophilic displacement of the 2-bromide proceeded cleanly with hot anhydrous sodium methoxide to give 2-methoxythiazole 130. Low-temperature metalation of 130 with n-butyl lithium occurred selectively at the 5-position (76), and subsequent electrophilic trapping with diethyl chlorophosphate produced the 5-phosphonate 131. Deprotection of 131 was accomplished either stepwise with mild acid to pn uce the thiazolin-2-one intermediate 132, or directly with trimethylsilyl bromide to give the free phosphonic acid 133, which was isolated as its cyclohexylammonium salt. 

The transformation of the terminal bromo substituents to carboxylic acid functions with (i) n-butyl lithium (ii) carbon dioxide, provides water soluble derivatives of 47 which are interesting as models for unimolecular micelles. 

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