Substituted and derivatives

VI. Composition in Aqueous Solution Substituted and Derived Sugars. 42... 

The complexes [ N[CH2CH2NSiMc3]3 AnCl]2 (An = Th, U) were first reported the molecular structure of the uranium complex demonstrated it was dimeric in the solid state. The chloride ligand may be substituted, and derivatives incorporating cyclopentadienyl, borohydride, alkoxide, amide, and diazabutadiene derivatives have been characterized. Attempts to alkylate the... 

The history, world consumption, and production, analogues, substitutes, and derivatives of linalool have been reviewed by Clark (151). Estimates of market size vary. Another source (83) estimates the total production volume of linalool and its esters as 6000 tpa, whereas Clark (151) states that the output of three of the main producers is 10,000 tpa. Such variances probably stem from the fact that linalool is used per se and as an intermediate for both other aroma chemical and vitamin manufacture and the result will depend on how the volume is estimated. 

The remainder of this section describes the commercially important isomer /-menthol (42) the natural sources, world consumption, synthesis, properties, analogues, substitutes, and derivatives of which have been reviewed by Clark [187, 188]. The Leffingwell website (189) also contains a large amount of information on menthol. 

A point in case is provided by the bromination of various monosubstituted benzene derivatives it was realized that substituents with atoms carrying free electron pairs bonded directly to the benzene ring (OH, NH2, etc) gave 0- and p-substituted benzene derivatives. Furthermore, in all cases except of the halogen atoms the reaction rates were higher than with unsubstituted benzene. On the other hand, substituents with double bonds in conjugation with the benzene ring (NO2, CHO, etc.) decreased reaction rates and provided m-substituted benzene derivatives. 

Figure 2-62. The substituted phenyl derivative is an example of a typical Markush structure. Herein, a number of compounds are described in one structure diagram by fill-ins. Phenylalanine is one of these structures when r is COOH, is H, and X is H.

The growing importance of cyclopropane derivatives (A. de Meijere, 1979), as synthetic intermediates originates in the unique, olefin-like properties of this carbocycle. Cyclopropane derivatives with one or two activating groups are easily opened (see. p. 69f.). Some of these reactions are highly regio- and stereoselective (E. Wenkert, 1970 A, B E. J. Corey, 1956 A, B, 1975 see p. 70). Many appropriately substituted cyclopropane derivatives yield 1,4-difunctional compounds under mild nucleophilic or reductive reaction conditions. Such compounds are especially useful in syntheses of cyclopentenone derivatives and of heterocycles (see also sections 1.13.3 and 4.6.4). 

Several substituted cyclohexane derivatives may also be obtained by the reduction of a benzenoid precursor. Partial reduction of resorcinol, for example, and subsequent methyla-tion yields 2-methylcyclohexane-I,3-dione, which is frequently used in steroid synthesis (M.S. Newman, 1960 see also p. 71f.), From lithium-ammonia reduction of alkoxybenzenes l-alkoxy-l,4-cyclohexadienes are obtained (E.J. Corey, 1968 D). 

Reactivity of A-4-thiazoline-2-thiones and derivatives involves four main possibilities nucleophilic reactivity of exocyclic sulfur atom or ring nitrogen, electrophilic reactivity of carbon 2 and electrophilic substitution on carbon 5. 

A great number of various substituted aminophenyl derivatives of thiazolium, and their organic or metallic complexes, have been patented as weed-killers or regulating growth factors of plants (135-138). 

Many methine cationic dyes, styrylic (141), pyrrolic. or amino-substituted (142) derivatives of thiazolium, possess interesting anthelmintic properties (143). This last class has been used as accelerators of the catabolism and activators of cellular exchanges (144). 

Out-of-Plane Vibrations, yCH and yCD. In accordance with all the proposed assignments (201-203), the bands at 797 and 716 cm correspond to yCH vibrators, which is confirmed by the C-type structure observed for these frequencies in the vapor-phase spectrum of thiazoie (Fig. 1-9). On the contrary, the assignments proposed for the third yCH mode are contradictory. According to Chouteau et al. (201), this vibration is located at 723 cm whereas Sbrana et al. (202) prefer the band at S49cm and Davidovics et al. (203) the peak at 877 cm This last assignment is the most compatible with the whole set of spectra for the thiazole derivatives (203) and is confirmed by the normal vibration mode calculations (205) (Table 1-25). The order of decreasing yCH frequencies, established by the study of isotopic and substituted thiazole derivatives, is (203) yC(4)H > 70(2)13 > yC(5)H. Both the 2- and 4-positions, which seem equivalent for the vCH modes, are quite different for the yCH out-of-plane vibrations, a fact related to the influence observed for the... 

II. Thiazoles from a-Halocarbonyl Compounds and Derivatives 211 2. Reaction with N>Substituted Thioamides (ThiazoHum Salts)... 

Carbon disulfide readily reacts with a-aminonitriles giving 2-mercapto-5-aminothiazoles (213), (271, 293) which can be converted to 5-aminothiazoles unsubstituted in the 2-position (Scheme 110 and Table II-34a). If this reaction is carried out in the presence of benzyl chloride in phosphorus tribromide, a 2-S-substituted thiazole derivative (214) is obtained in quantitative yield (Scheme 111), with R = hydrogen or phenyl (68, 304). 

The spectra of substituted thiazole derivatives, especially the methyl derivatives, can be used to determine harmonic and combination bands of the T(ch) modes 27(c.,h> T(c.hi + T[Pg.351]

An old name for benzene was phene and its hydroxyl derivative came to be called phe nol This like many other entrenched common names is an acceptable lUPAC name Likewise o m and p cresol are acceptable names for the various ring substituted hydroxyl derivatives of toluene More highly substituted compounds are named as deriv atives of phenol Numbering of the ring begins at the hydroxyl substituted carbon and proceeds m the direction that gives the lower number to the next substituted carbon Sub stituents are cited m alphabetical order... 

The name phenylene o-, m-, or p-) is retained for the radical —C5H4—. Bivalent radicals formed from substituted benzene derivatives and having the free valences at ring atoms are named as substituted phenylene radicals, with the carbon atoms having the free valences being numbered 1,2-, 1,3-, or 1,4-, as appropriate. 

Table 7.9 Electronic Absorption Bands for Representative Chromophores Table 7.10 Ultraviolet Cutoffs of Spectrograde Solvents Table 7.11 Absorption Wavelength of Dienes Table 7.12 Absorption Wavelength of Enones and Dienones Table 7.13 Solvent Correction for Ultraviolet-Visible Spectroscopy Table 7.14 Primary Bands of Substituted Benzene and Heteroaromatics Table 7.15 Wavelength Calculation of the Principal Band of Substituted Benzene Derivatives...

H-nmr chemical shifts of N-1—H and N-3—H signals have been used as a criterion for distinguishing between N-l-substituted and N-3-substituted hydantoin derivatives (22). They can often be related to electronic properties, and thus good linear correlations have been found between the shifts of N—H and Hammett parameters of the substituents attached to the aryl group of 5-arylmethylenehydantoins (23). 

Primary nitroparaffins react with two moles of formaldehyde and two moles of amines to yield 2-nitro-l,3-propanediamines. With excess formaldehyde, Mannich bases from primary nitroparaffins and primary amines can react further to give nitro-substituted cycHc derivatives, such as tetrahydro-l,3-oxa2iaes or hexahydropyrimidines (38,39). Pyrolysis of salts of Mannich bases, particularly of the boron trifluoride complex (40), yields nitro olefins by loss of the amine moiety. Closely related to the Mannich reaction is the formation of sodium 2-nitrobutane-1-sulfonate [76794-27-9] by warming 1-nitropropane with formaldehyde and sodium sulfite (41). 

Dialkyl peroxides have the stmctural formula R—OO—R/ where R and R are the same or different primary, secondary, or tertiary alkyl, cycloalkyl, and aralkyl hydrocarbon or hetero-substituted hydrocarbon radicals. Organomineral peroxides have the formulas R Q(OOR) and R QOOQR, where at least one of the peroxygens is bonded directly to the organo-substituted metal or metalloid, Q. Dialkyl peroxides include cyclic and bicycflc peroxides where the R and R groups are linked, eg, endoperoxides and derivatives of 1,2-dioxane. Also included are polymeric peroxides, which usually are called poly(alkylene peroxides) or alkylene—oxygen copolymers, and poly(organomineral peroxides) (44), where Q = As or Sb. 

Other Electrophilic Reactants. ReversibHity of the electrophilic reactions enables substituted dye derivatives to be obtained. Thus, the halogenation of cyanines, oxonoles, and merocyanines has been studied (3,65,66). Halogen atoms are mobHe in the polymethine chain, and the derivatives themselves can function as halogenation reagents. 

The reaction of methoxy-substituted 1,4-dihydroatomatic systems is a general one. Other condensed systems react ia a similar manner, for example, 3,6-dimethoxy-1,4,S,8-tetrahydronaphtha1ene and derivatives of anthracene (35) and xanthene (36) (74). The proposed method enables synthesis of the tri-and tetracarbocyanines where the whole chromophore is iategrated iato a rigidizing skeleton. Asymmetrical polymethines can also be obtained similarly. 

The most powerful method for stmcture elucidation of steroid compounds during the classical period of steroid chemistry (- 1940 1950s) was ir-spectroscopy. As with the ultraviolet spectra, data collected on the infrared spectra of steroids are available in several books, spectmm atiases, and review articles (265,266). Unlike ultraviolet spectroscopy, even the least substituted steroid derivatives are relatively rich in characteristic absorption bands in infrared spectroscopy (264). 

Etherification. The reaction of alkyl haUdes with sugar polyols in the presence of aqueous alkaline reagents generally results in partial etherification. Thus, a tetraaHyl ether is formed on reaction of D-mannitol with aHyl bromide in the presence of 20% sodium hydroxide at 75°C (124). Treatment of this partial ether with metallic sodium to form an alcoholate, followed by reaction with additional aHyl bromide, leads to hexaaHyl D-mannitol (125). Complete methylation of D-mannitol occurs, however, by the action of dimethyl sulfate and sodium hydroxide (126). A mixture of tetra- and pentabutyloxymethyl ethers of D-mannitol results from the action of butyl chloromethyl ether (127). Completely substituted trimethylsilyl derivatives of polyols, distillable in vacuo, are prepared by interaction with trim ethyl chi oro s il an e in the presence of pyridine (128). Hexavinylmannitol is obtained from D-mannitol and acetylene at 25.31 MPa (250 atm) and 160°C (129). 

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