N substituted

If the amide is an N-(mono- or di)-substituted amide, or the imide an N-substituted imide, the above alkaline hydrolysis will give a solution... 

Acetanilide, benzanilide and their nuclear- and N-substituted derivatives. 

N-Substituted phthalimides. Phthalic anhydride reacts with primary amines only to yield N-substituted phthaUmides ... 

Dissolve 0 5 g. of the primary amine and 0-5 g. of pure phthaUc anhydride in 5 ml. of glacial acetic acid and reflux for 20-30 minutes. (If the amine salt is used, add 1 g. of sodium acetate.) The N-substituted phthaUmide separates out on cooling. Recrystallise it from alcohol or from glacial acetic acid. 

The independent preparation of potassium phthabmide (from a solution of phthalimide in absolute ethanol and potassium hydroxide in 75 per cent, ethanol) may be avoided in many cases by boiling phthalimide with the halide in the presence of anhydrous potassium carbonate. The N-substituted phthalimide (I) is frequently cleav with difficulty this is often facilitated by reaction with hydrazine hydrate to give an intermediate product, which is easily decomposed by hydrochloric acid to 3deld the insoluble hydrazide of phthaUc acid (II) and the primary amine (III) ... 

The modified procedure involves refluxing the N-substituted phthaUmide in alcohol with an equivalent quantity of hydrazine hydrate, followed by removal of the alcohol and heating the residue with hydrochloric acid on a steam bath the phthalyl hydtazide produced is filtered off, leaving the amine hydrochloride in solution. The Gabriel synthesis has been employed in the preparation of a wide variety of amino compounds, including aliphatic amines and amino acids it provides an unequivocal synthesis of a pure primary amine. 

A very mild and efficient synthesis of N-substituted -lactams uses the Mitsunobu reaction (see section 2.6.2) for the ring closure of seryl dipeptides protected at the terminal N as 4,5-diphenyloxazol-2(3f/)-one ( Ox ) derivatives (see section 2,6.3)... 

N-Substituted arylhydroxylamities add to methyl propyiioate and rearrangement occurs to give indolc-3-carboxylate esters[3]. With unsubstituted... 

Maleic anhydride condenses with 2-aminothiazole-4-carboxylic acid giving the raaleimide 107 (269) another report claims, however, that the reaction of 2-amino-4-methylthiazole with this anhydride gives the N-substituted maleamic acid (108) (Scheme 73) (270). 

A-4-Thiazoline-2-thiones can be obtained directly from 2-thiazolyldiazonium tetrafiuoroborate by reaction with an excess of thiourea (9). When 1 1 stoichiometry is used, the adduct (7) can be isolated. Further treatment of 7 with an excess of thiourea leads to the 2-mercaptolhiazole (3) 9). 2-Iminothiazoles 81 when heated at 150°C with CSt sive N-substituted A-4-thiazofine-2-thiones (9) (Scheme 31... 

Reaction takes place on nitrogen when the electrophilic center is an sp carbon, particularly if it is charged. Thus Mannich reaction yields the N-substituted compound (71 and 72) (Scheme 34) (54. 157-159). The same reaction is reported with piperidine, o-toluidine. and methylaniline (158). 

Acrylonitrile reacts with the sodium salt of 4.5-dimethvl-A-4-thiazoline-2-thione (73J (R4 = R5 = Me) to yield 3-(2-cyanoethyl)-4.5-dimethyl-A-4-thiazoline-2-thione (74) (R4 = R, = Me) (Scheme 35 (160). Humphlett s studies of this reaction showed that the size of the R4 substituent is a determinant factor for the S versus N ratio (161. 162). If R4 == H, 100% of the N-substituted product (74) is obtained this drops to 50% when R4 = methyl, and only the S-substituted product (75) is obtained when R4 = phenyl. The same trend is observed with various CH2 = CH-X (X = C00CH3. COCH3) reagents (149). The S/N ratio also depends on the electrophilic center for CH2 = CH-X systems thus S-reaction occurs predominantly with acrylonitrile, whereas N-substitution predominates with methvlvinvlketone (149). 

Alkylation by diazoalkanes gives more N-substituted product when the reaction goes through an S l transition state. Representative data are given in Table Vll-lOa. and they are discussed in Ref. 101. 

Alkylation of A-4-thiazoline-2-one may yield O-R or N-R derivatives according to experimental conditions. With diazomethane in ethanol O-raethylation takes place (29. 36. 214). N-Methylation is reported when a basic solution of A-4-thiazoline-2-one reacts with methyl iodide or dimethylsulfate (21, 29, 215, 216), Reaction of l-chloro-2-dimethyl-aminoethane with the sodium salt of 4 R-A-4-thiazoline-2-one (91) in alcohol, first claimed to yield the aminoalkylether (217, 218), was shown after infrared investigation to give the N-substituted derivative (92) (107), even when R Ph (Scheme 45). More probably the site of reaction in... 

N-substituted selenoureas give the same condensation reaction (Scheme 9. Table X-3). 

Similarly 2- and 4-disubstituted seienazolidines were prepared from 2-methyl- and 2,2-dimethylaziridines (Table X-17i (74) and 2- and 3-disubstituted seienazolidines were obtained from N-substituted aziridines (Table X-18) (74). 

In 1908, Korner (77) developed the synthesis of N-substituted rhodanines (55) from dithiocarbaminacetic acid ... 

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

Thiazolium salts with alkyl (103, 722), arylalkyl (116), aryl (305), or heteroaryl (96) substituents on the nitrogen have been also prepared by this procedure. As in the thiazole series, N-substituted thioamides can be formed directly in the reaction mixture from phosphorus pentasulfide and N-substituted amides (127). These methods are important in the synthesis of thiamine 102 (vitamin Bj) (Scheme 45). 

The cyclization of N-substituted thioureas (123) with halocarbonyl compounds gives 2-monosubstituted aminothiazoles (124) (Scheme 58)... 

The N-substituted derivatives (175) are also obtained from salts of N-monosubstituted dithiocarbamic acid (174) (Scheme 89) (35, 348). 

N-Substituted aminothiazoles, with R = H, Me, CHMCj, R, =H. Me-Rz = H, Me, CHMcj, Ph, and Rj, R2 = CH2CH2, have been recently obtained by condensing thioureas with 1,2-dichloroethylisothiocyanate (Scheme 131) (805). 

N substituted imines are sometimes called Schiff s bases after Hugo Schiff a German chemist who de scribed their formation in 1864... 

Primary amines (RNH2) yield N substituted amides (R CNHR)... 

Secondary and tertiary amines are named as N substituted derivatives of primary amines The parent primary amine is taken to be the one with the longest carbon chain The prefix N is added as a locant to identify substituents on the ammo nitrogen as needed... 

A/-Methylethylamine (given as CH3NHCH2CH3 in the pre ceding example) is an N substituted derivative of ethanamine it is A/-methyl ethanamine... 

Primary amines undergo nucleo philic addition to the carbonyl group of aldehydes and ketones to form carbinol amines These carbinolamines dehydrate under the conditions of their formation to give N substituted imines Secondary amines yield enamines... 

Secondary amines are prepared by hydrogenation of a carbonyl compound m the presence of a primary amine An N substituted mine or Schijfs base is an intermediate... 

The remaining step is to eliminate those terms which refer to the subchain by expressing them in terms of the polymer molecule as a whole. Specifically, we recall that (r ) = n l, = n f, and = n/n. Substituting into Eq. (3.97),... 

Applications. Among the P—O- and P—N-substituted polymers, the fluoroalkoxy- and aryloxy-substituted polymers have so far shown the greatest commercial promise (14—16). Both poly[bis(2,2,2-trifluoroethoxy)phosphazene] [27290-40-0] and poly(diphenoxyphosphazene) [28212-48-8] are microcrystalline, thermoplastic polymers. However, when the substituent symmetry is dismpted with a randomly placed second substituent of different length, the polymers become amorphous and serve as good elastomers. Following initial development of the fluorophosphazene elastomers by the Firestone Tire and Rubber Co., both the fluoroalkoxy (EYPEL-F) and aryloxy (EYPEL-A) elastomers were manufactured by the Ethyl Corp. in the United States from the mid-1980s until 1993 (see ELASTOLffiRS,SYNTHETic-PHOSPHAZENEs). 

Applications. Polymers with small alkyl substituents, particularly (13), are ideal candidates for elastomer formulation because of quite low temperature flexibiUty, hydrolytic and chemical stabiUty, and high temperature stabiUty. The abiUty to readily incorporate other substituents (ia addition to methyl), particularly vinyl groups, should provide for conventional cure sites. In light of the biocompatibiUty of polysdoxanes and P—O- and P—N-substituted polyphosphazenes, poly(alkyl/arylphosphazenes) are also likely to be biocompatible polymers. Therefore, biomedical appHcations can also be envisaged for (3). A third potential appHcation is ia the area of soHd-state batteries. The first steps toward ionic conductivity have been observed with polymers (13) and (15) using lithium and silver salts (78). 

Preparation from Amines. The most common method of preparing isocyanates, even on a commercial scale, involves the reaction of phosgene [75-44-5] and aromatic or aUphatic amine precursors. The initial reaction step, the formation of N-substituted carbamoyl chloride (1), is highly exothermic and is succeeded by hydrogen chloride elimination which takes place at elevated temperatures. 

With sodium azide, salts of secondary nitroparaffins rearrange to N-substituted amides (29). With SO2, primary or secondary nitroparaffins give imidodisulfonic acid salts (30). Potassium nitroform reacts quantitatively with nitryl chloride in ether to form tetranitromethane (31). 

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