0-Alkyl derivatives

2 Alkyl derivatives. A H and Li n.m.r. study of (1) also revealed the presence in THF of dimers and tetramers, equation (1)  

4 Alkyl derivatives. Mass peaks corresponding to (1) and the less 

The crystal structure and C n.m.r. spectrum of monomeric (Ph2P)2CHLi. 

TMED have been reported Li is co-ordinated to bothPatoms (Li-P 2.58(2) 8). 

5 Enolatesand related derivatives. The lithium enolate of CH CHO (CH2 CH0Li) is tetrameric in THF with a barrier to rotation about the vinyl bond of 

The solid state structures (as well as those in solution) have been determined for the dimeric species (i) lithiated 2-Me02 Cyclohexanone dimethylhydrazone 

2 Alkyl Derivatives. - Alkyllithium compounds have continued in 2000 to be a very useful synthetic tool. They have been employed in many transformations both in their own right and in order to afford new lithium reagents in situ. For example, their reaction with heavier Group 1 metal alkoxides is known to result in metal interchange and the formation of heavy metal alkyls this in turn leads to a marked increase in reaetivity. The synthesis of these so-called superbases has lately been the subject of review.  

OrganometalUc Chemistry, Volume 30 The Royal Society of Chemistry, 2002 

The reaction of 1,1-dichloroethane with any one of a number of organolithium substrates yields 1,1-dichloroethyllithium - a metallating agent capable of reacting with alkyl carboxylates to give the corresponding a,a-dichloro- or a-chloro-ethyl ketones or with ethyl carboxylates to give 2,2-dichloro-f-alkyl-l-ethoxy-l-(trimethylsiloxy)propanes.  

Moving on to solid-state structure elucidation, a review has reeently been published on the fully characterised examples of ehiral dilithiomethane analogues that have been derived from sulfoximines. Two methanide salts - (THF)3 Li Li[C(SiMe3)3]2 and its decomposition product 

Reports of mono- and dilithiated organie eompounds containing diphenyl- 

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On acetylation it gives acetanilide. Nitrated with some decomposition to a mixture of 2-and 4-nitroanilines. It is basic and gives water-soluble salts with mineral acids. Heating aniline sulphate at 190 C gives sulphanilic add. When heated with alkyl chlorides or aliphatic alcohols mono- and di-alkyl derivatives are obtained, e.g. dimethylaniline. Treatment with trichloroethylene gives phenylglycine. With glycerol and sulphuric acid (Skraup s reaction) quinoline is obtained, while quinaldine can be prepared by the reaction between aniline, paraldehyde and hydrochloric acid. 

Used industrially to cross-link hydroxylic polymers, polyethyleneimine. Possesses some carcinogenic properties. Polyethyleneimine is a hygroscopic liquid used in paper manufacture to confer wet strength and in textiles, alkylated derivatives also form useful polymers. 

Hydrazine and its alkylated derivatives are used as rocket fuels in organic chemistry, substituted phenylhydrazines are important in the characterisation of sugars and other compounds, for example aldehydes and ketones containing the carbonyl group C=0. 

Pseudo-saccharin ethers. Pseudo-saccharin chloride (Section VII,26) reacts with alcohols to give ethers (0 alkyl derivatives of saccharin) ... 

While both 2- and 3-vinylindole have been synthesized and characterized[l,2], they arc quite reactive and susceptible to polymerization. This is also true for simple l-alkyl derivatives which readily undergo acid-catalysed dimerization and polymerization[3]. For this reason, except for certain cases where in situ generation of the vinylindoles is practical, most synthetic applications of vinylindoles involve derivatives stabilized by EW-nitrogen substituents[4]. 

Acetamidothiazole and its 4-alkyl derivatives react with chloro-sulfonic acid. The structure of the resulting products was a subject of controversy (172. 393-397). N-acetyl-A -(2-thiazolyl)-sulfamoyl chlorides (189) first proposed were then shown to be 2-acetamido-5-chloro-sulfonylthiazoles (190) (Scheme 120) (367. 368. 398). the latter assignment is based on infrared (368) and chemical evidence (367). 

Auto-association of A-4-thiazoline-2-thione and 4-alkyl derivatives has been deduced from infrared spectra of diluted solutions in carbon tetrachloride (58. 77). Results are interpretated (77) in terms of an equilibrium between monomer and cyclic dimer. The association constants are strongly dependent on the electronic and steric effects of the alkyl substituents in the 4- and 5-positions, respectively. This behavior is well shown if one compares the results for the unsubstituted compound (K - 1200 M" ,). 4-methyl-A-4-thiazoline-2-thione K = 2200 M ). and 5-methyl-4-r-butyl-A-4-thiazoline-2-thione K=120 M ) (58). 

Alkylselenazoles are oily alkaline liquids possessing a smell similar to that of the corresponding thiazole or pyridine derivatives. The crystalline picrates or 3-methylselenazolium iodides have been used for the purpose of characterization. Alkyl derivatives are partially soluble in water aryl derivatives are insoluble. 

In 1890, Gabriel and Lauer (92) established that a-bromoamines react with CS2 to give 2-mercaptothiazolines (61). In the same laboratory, Hirsch (93) reacted /x-mercapto -methylthiazoline (61) with various alkyl iodides and obtained the corresponding S-alkyl derivatives. 

The molar refraction deduced for alkyl derivatives, compared to the value obtained by addition, to the experimental molar refraction of thiazole, of the classical (CH2) increment of Eisenlohr Rch 4.618 cm ), show specific exaltations which are typical for each position of the thiazole ring (Table 1-49). 

Potentiometric determinations of the pK of thiazole and essentially its alkyl derivatives are summarized in Table T50. The most reliable values are given by Phan-Tan-Luu et al. (321), who realized a critical study of the classical Henderson method for the determination of pK. ... 

Thiazole acetic acids and their hotnologs can also be prepared by cyclization procedures 4-thiazole alkanoic acids and their salts were prepared by treating a thioamide with a -y-chloro- or 7-bromoacetoacetic or their a-alkyl derivatives (4, 10, 16, 22, 273, 275, 281, 640, 647, 695). 

The object of these studies has been the determination of the degree of association in thiazole and its alkyl derivatives. Various solvents have been used cyclohexane (154), carbon tetrachloride (155, 156), benzene and nitrobenzene (157). 

The quatemization reaction of the thiazole nitrogen has been used to evaluate the steric effect of substituents in heterocyclic compounds since thiazole and its alkyl derivatives are good models for such study. In fact, substituents in the 2- and 4-positions of the ring only interact through their steric effects (inductive and resonance effects were constant in the studied series). The thiazole ring is planar, and the geometries of the ground and transition states are identical. Finally, the 2- and 4-positions have been shown to be different (259. 260). 

The alkyl derivatives of thiazoles can be catalytically oxidized in the vapor phase at 250 to 400°C to afford the corresponding formyl derivatives (21). Molybdenum oxide, V2O5, and tin vanadate are used as catalysts either alone or with a support. The resulting carbonyl compounds can be selectively oxidized to the acids. 

The acetoacetic ester synthesis brings about the overall transformation of an alkyl halide to an alkyl derivative of acetone... 

Converting the C 2 alkylated derivative to the corresponding malonic acid deriva tive by ester hydrolysis gives a compound susceptible to thermal decarboxylation Tern peratures of approximately 180°C are normally required... 

Thiourea (H2NCNH2) reacts with diethyl malonate and its alkyl derivatives in the same way that urea does Give the structure of the product obtained when thiourea is used instead of urea in the synthesis of pentobarbital The anesthetic thiopental (Pentothal) sodium is the sodium salt of this product yWhat IS the structure of this compound ... 

Section 21 9 Michael addition of the enolate ions derived from ethyl acetoacetate and diethyl malonate provides an alternative method for preparing their a alkyl derivatives... 

The Kolbe-Schmitt reaction has been applied to the preparation of other o hydroxy benzoic acids Alkyl derivatives of phenol behave very much like phenol itself... 

Ketenes c=c=o 2060-2040 (vs) 1130 (s) 1374 (s) 1120 (s) Pseudo-asymmetric stretching Pseudo-symmetric stretching Alkyl derivatives Aryl derivatives... 

The amide group is readily hydrolyzed to acrylic acid, and this reaction is kinetically faster in base than in acid solutions (5,32,33). However, hydrolysis of N-alkyl derivatives proceeds at slower rates. The presence of an electron-with-drawing group on nitrogen not only facilitates hydrolysis but also affects the polymerization behavior of these derivatives (34,35). With concentrated sulfuric acid, acrylamide forms acrylamide sulfate salt, the intermediate of the former sulfuric acid process for producing acrylamide commercially. Further reaction of the salt with alcohols produces acrylate esters (5). In strongly alkaline anhydrous solutions a potassium salt can be formed by reaction with potassium / /-butoxide in tert-huty alcohol at room temperature (36). 

There is a wide variety of dyes unique to the field of hair coloring. Successive N-alkylation of the nitrophenylenediamines has an additive bathochromic effect on the visible absorption to the extent that violet-blue dyes can be formed. Since the simple A/-alkyl derivatives do not have good dyeing properties, patent activity has concentrated on the superior A/-hydroxyalkyl derivatives of nitrophenylenediamines (29,30), some of which have commercial use (31). Other substituents have been used (32). A series of patents also have been issued on substituted water-soluble azo and anthraquinone dyes bearing quaternary ammonium groups (33). 

The first resins to be produced on a commercial scale were the coumarone—indene or coal-tar resins (1) production in the United States was started before 1920. These resins were dominant until the development of petroleum resins, which were estabHshed as important raw materials by the mid-1940s. Continued development of petroleum-based resins has led to a wide variety of aHphatic, cyclodiene, and aromatic hydrocarbon-based resins. The principal components of petroleum resins are based on piperylenes, dicyclopentadiene (DCPD), styrene, indene, and their respective alkylated derivatives. 

Naphthalenol also is used ia the preparation of azo, iadigoid, and nitro, eg, 2,4-dinitro-l-naphthol, dyes, and ia making dye iatermediates, eg, naphtholsulfonic acids, 4-chloro-1-naphthalenol, and l-hydroxy-2-naphthoic acid. 1-Naphthalenol is an antioxidant for gasoline, and some of its alkylated derivatives are stabilizers for plastics and mbber (68). 

Dimethoxy-/)-benzoquiQone is a naturally occurring antiinflammatory (238). 3-Alkyl derivatives of it have also been prepared (239). 

Reaction with All l and Arall l Halides. Alkyl haUdes form A/-alkyl derivatives of alkanolamines. 

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