The preparation of derivatives

Note. Secondary amines, etc. in Class (ii) can be identified by their derivatives (C) and (D) above, and by their picrates when these can be readily isolated. The preparation of derivatives (D) requires the dry amine, whereas water does not aifect that of derivatives (C). 

Di- and poly-halogenated aliphatic hydrocarbons. No general procedure can be given for the preparation of derivatives of these compounds. Reliance must be placed upon their physical properties (b.p., density and refractive index) and upon any chemical reactions which they undergo. 

Experimental details for the preparation of derivatives with benzoyl chloride and with 3-nitrophthalic anhydride are given in Section IV,100,2 and 7. 

Hinsberg procedure for the separation of primary, secondary and tertiary amines is given under (viii) above, and this method may be used. The following experimental details may, however, be found useful for the preparation of derivatives of primary and secondary amines. 

The most important use of diketene is for the preparation of derivatives of acetoacetic acid, such as acetoacetate esters, acetoacetamides, and chloroacetoacetates, which have found many uses in life sciences, dyestuffs, adhesives, and coatings. 

Preparation and Properties of Organophosphines. AUphatic phosphines can be gases, volatile Hquids, or oils. Aromatic phosphines frequentiy are crystalline, although many are oils. Some physical properties are Hsted in Table 14. The most characteristic chemical properties of phosphines include their susceptabiUty to oxidation and their nucleophilicity. The most common derivatives of the phosphines include halophosphines, phosphine oxides, metal complexes of phosphines, and phosphonium salts. Phosphines are also raw materials in the preparation of derivatives, ie, derivatives of the isomers phosphinic acid, HP(OH)2, and phosphonous acid, H2P(=0)0H. 

The L-xylosone pathway to L-ascorbic acid was never commercialized because L-xylosone was not teaddy available and was too expensive to prepare. The route, however, was valuable for L-ascorbic acid stmcture determination and for the preparation of derivatives. 

Sulfonation with sulfur trioxide, pyridine sulfur trioxide, pyridine bis-sulfur trioxide, and dioxane sulfur trioxide, which are useful sul-fonating agents for acidophobic substances, have been applied to the thiophene seriesd At room temperature the 2-monosulfonic acid (isolated as the barium salt) is obtained in 86% yield. Higher temperatures lead to a disulfonic acid. However, sulfonation with chloro-sulfonic acid appears to be more convenient,as the sulfonyl chloride obtained can be used directly for the preparation of derivatives. 

Oxidation with potassium permanganate was also used for the preparation of derivatives with a CH3(CH2)n (n = 2,4,6,8,12) and j0-substituted vinyP - group in the 6-position from the corresponding thioxo derivatives. ... 

However, for the preparation of derivatives which contain a functional group directly attached to position 6, the application of the foregoing cyclization method is considerably limited by the availability or existence of the required derivatives of -keto acids and may also be affected by differences in their reactivity. Cyclization of thiosemicarbazones was, therefore, used for these substances only in the case of the 6-carboxylic acid (see also Section II,B,2,a). Of the other derivatives known, the 6-acetic acid ester should be mentioned. Recently some further derivatives of dioxotriazine-6-carboxylic acid were reported. ... 

Deoxy-sugars. Part XVII. An Investigation of the Glycal Method for the Preparation of Derivatives of 2-Deoxy-D-galactose, W. G. Overend, F. Shafizadeh, and M. Stacey, /. Chem. Soc., (1951) 992-993. 

The antitumor alkaloid ellipticine (5,1 l-dimethyl-6//-pyrido[4,3-b]carbazole) has been isolated from many species of Ochrosia and Aspidosperma. Ellipticine and its derivatives are highly active versus several experimental neoplasms, and the compound has been widely subjected to studies devoted to its total synthesis, the preparation of derivatives, and metabolism. Metabolic transformation studies with ellipticines have been conducted, using microorganisms, in vivo and in vitro... 

In order to increase the Lewis acidity of the indium centers in compounds such as 52, the preparation of derivatives that incorporate a tetrafluorophenylene backbone has also been pursued. l,2-Bis(halomercurio)tetrafluorobenzene (halide = chloride (53) or bromide (54)) reacts with two equivalents of the corresponding indium(I) halide in THF at 25 °C to afford the tetrakis(T i ) adduct of the respective 9,10-dihalo-9,10-dihydro-9,10-diinda-octafluoroanthracene (halide = chloride (55) or bromide (56)) (Scheme 22). Compound 56 is also prepared by the reaction of (o-C6F4Hg)3 (4) with InBr in refluxing toluene followed by treatment with THF. The formation of the diindacycles 55 and 56 in the reaction of 53 and 54 with two equivalents of the corresponding indium(I) halide is surprising since, in principle, bis(indiumdihalide) complexes would be the expected products. This cyclization... 

There are two reports describing the preparation of derivatives of 1,2-thiazetidine-1,1-dioxide. The sulfur atom in L-cystine diethyl ester was oxidized and the corresponding sulfonyl chloride was cyclized with ammonia (Scheme 3) (60CB784). A similar transformation used protected )3-homocysteine as starting material (94LA251). 

In the reaction of 4-diazopyrazoles with Grignard halides, 4-alkylazo or 4-arylazo derivatives of type 205 were obtained, sometimes with traces of the corresponding dediazoniated pyrazoles (74YZ23). This reaction was successfully employed in the preparation of derivatives (R = alkyl) that could not be obtained by the coupling reaction. 

J. Hill, L. Hough, and A. C. Richardson, Nucleophilic replacement reactions of sulphonates. I. The preparation of derivatives of 4,6-diamino-4,6-dideoxy-D-glucose and -D-galactose, Carbohydr. Res., 8 (1968) 7-18. 

The following references extend the literature coverage up to December 31, 1975. The preparation of derivatives of one previously unknown type A meso-ionic system has come to the attention of the authors since the completion of the Appendix. These new meso-ionic compounds are l,2,3-thiadiazole-5-ones [Table A-I (page 111) a = S, b = N, c = NR, d = CR, e = C, f = O]. They are the first examples of sulfur analogs of the sydnones (1). 

The first reported use of a polysaccharide as a CSP was by Krebs and co-workers18 20, who used readily available and inexpensive crystalline cellulose as plain CSP beads. This work was followed by the preparation of derivatives of linear polymers of saccharides (Figure 2), many of which have proved useful, particularly for preparative separations. 

The first pyrazolo[l,5-c]pyrimidine derivative (191) was prepared by condensing thiosemicarbazide with heptane-2,4,6-trione in the presence of perhydroacetic acid (72CB388). This reaction was adopted for the preparation of derivatives of 191 (X = O, NH), and later used to synthesize other pyrazolo[ 1,5-c] pyrimidines (71GEP2131790). 

The preparation of derivative 333 was described in 1909 by Sachs who treated 1,8-diaminonaphthalene with selenous acid (H2SeO3). The chemistry of this molecule has not been investigated. 

No naturally occurring 1,2,4-thiadiazole having been reported so far, all compounds are of synthetic origin. The parent of the series, 1,2,4-thiadiazole, was first synthesized in 1955s by the sequence of reactions 8->9—>-10->-2,B 6 but remains relatively inaccessible. Because of its sensitivity it is not a practicable starting material for the preparation of derivatives these are therefore always built up directly by suitable cyclization reactions and subsequent modification of the substituentB as required. This section is confined to direct syntheses the numerous interconversions that furnish additional derivatives from the preformed 1,2,4-thiadiazole nucleus are considered with the chemical properties of the individual classes of compounds. 

Studies of other Polygonum species are under way to establish the presence of homologs of the vanicosides. Isolation and structure elucidation of these homologs, along with the preparation of derivatives by synthetic methodology, will facilitate the establishment of a library of compounds which will be screened for PKC inhibitory activity. The results will produce a better understanding of the structure-activity relationships inherent in this class of phenylpropanoid glycosides. 

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