V-Alkyl Derivatives

Castillo, J.A., Calveras, J., Casas, J. et al. (2006) Fructose-6-phosphate aldolase in organic synthesis preparation of D-fagomine, /V-alkylated derivatives, and preliminary biological assays. Organic Letters, 8, 6067-6070. 

Dihydropyridines and their /V-alkyl derivatives undergo anodic oxidation in basic medium to the corresponding pyridines (reaction 27). The process may be complicated by the presence of other moieties for example, a nitro group may reductively condense... 

Aqueous NaOH (15%, 15 ml), the alkylating agent (6.94 mmol) and TPA-Cl (19 mg, 0.35 mmol) are added to a stirred solution of the /V-tosylhydraz.onc (3.5 mmol) in CH2CI2 (15 ml) at room temperature. The mixture is stirred at room temperature (Table 5.23) and the organic phase is then separated, washed with H20 (2 x 20 ml), dried (Na2S04), and evaporated under reduced pressure to yield the /V-alkylated derivative. 

G. Legler and H. Liedtke, Glucosylceramidase from calf spleen. Characterization of its active site with 4-n-alkylumbelliferyl P-glucosides and V-alkyl derivatives of 1-deoxynojirimycin, Biol. Chem. Hoppe Seyler, 366 (1985) 1113-1122. 

Naphtholactam is a particularly important condensation component for preparing apocyanine dyes. At first only dyes unsubstituted at the lactam nitrogen atom were prepared and recommended for dyeing tanned cotton and wool [46], However, it was later found that the /V-alkyl derivatives dye polyacrylonitrile in very lightfast violet and blue shades (e.g., 20). 

For the syntheses of 2-amino(or 2-imino)-TAs 42,43, and 45 the condensation of acetylenic esters with thiourea and their /V-alkyl derivatives is used most often [62CPB19 64CPB683 67CB3671, 67CJC939 68CPB1351,... 

Note The alkylation of tautomeric 1,5-naphthyridinones usually gives /V-alkyl derivatives, but (9-alkylation has been achieved by treatment of the substrate silver salt with an alkyl halide the other likely route to (9-alkylation, treatment with an diazoalkane, has not been used in this series. 

A comparison of the N-H and V-alkyl derivatives of 6 showed the expected paramagnetic shifts for the 7- and N-alkyl resonances. 

One of the two hydrogen atoms of phosphoramidates can be temporarily blocked with a trimethylsilyl group. The sodium salt of diethyl V-(trimethylsilyl)phosphoramidate (102) reacted with alkyl bromides in benzene in the presence of 10 mol % of tetra-n-butylammonium bromide to afford, after desilylation, the corresponding V-alkyl derivatives (103) in 79-95% yields for primary alkyl halides. Secondary alkyl halides gave poor results (Scheme 43). The addition of the quaternary ammonium salt is essential to promote the alkylation reaction. Hexamethyldisilazane and its cyclic analogs can also be utilized in the preparation of amines under moderate conditions (Scheme 43). ... 

Autoxidation of N-hydroxyamphetamine gives the nitroso-derivative which isomerizes to the corresponding oxime. A variety of AT-oxygenated products which might arise by oxidation, in vitro or in vivo, of 3,4-dimethoxyamphetamine and its V-alkyl derivatives have been prepared. A similar study has been carried out on the metabolic oxidation products of norephedrine. ... 

In this system, amphetamine, 3,4-methylenedioxyamphetamine (MDA) and the /V-mcthyl and (V-ethyl analogues of the drugs were derivatized, with 4-chloroamphetamine being used as the internal standard. For powders, solutions were prepared at concentrations of 1 mg ml 1 in methanol and a 100 il aliquot blown dry under nitrogen. To the residue was added 50 xl of 0.5 M KOH and 500 xl of toluene. The mixture was then shaken for 30 s and centrifuged, after which the toluene layer was recovered and HFBA (5 p,l) added. The excess reagent was neutralized with 500 xl of 10% NaHC03 and an aliquot (1 xl) analysed by GC-MS. Each of the amphetamines and the /V-alkylated derivatives could be separated and identified on the basis of retention index and mass spectral data. 

Compound 120 can be alkylated at oxygen or nitrogen, depending on the reaction conditions (Eq. 29).41 Usually, N-alkylation to 47 was observed when 120 was treated in the presence of base in DMF with alkyl halides such as propargyl chloride or allyl bromide.40 41 However, treating 120 in DMF with NaHC03 and n-propyl bromide produced a small amount of the O-alkyl compound 121 (R = n-propyl) as well as the /V-alkyl derivative (47 R = n-propyl).41... 

Alkylation of 2-substituted quinazolin-4(3//)-ones by reaction with sodium hydride in dimethylformamide followed by alkylation provided O-and /V-alkyl derivatives. The extent of alkylation at the different sites was reasonably explained in terms of steric properties of the 2-substituents.107 The silver salt of quinazolin-4(3//)-one and tetra-0-acetyl-/J-D-glucopyrano-syl bromide gave a 40% yield of the 0-glycosyl derivative in contrast with the mercury salt, which gave mainly the N-3-glycosyl derivative. As in the alkylation of mercapto compounds, quinazoline-4(3//)-thione gave the S-glycosyl derivative. If sodium hydroxide was used as base a 56% yield of the... 

The use of an alkylammonium chloride in place of NH4CI in reaction 12.58 leads to the formation of an (V-alkyl derivative (C1BNR)3 which can be converted to (HBNR)3 by treatment with Na[BH4]. 

The alkaloids and their transformation products are listed in alphabetical order in Table 2, while the derivatives have been listed in the order (a) quaternary ammonium salts, (b) V-alkyl derivatives, and (c) 0- and V-acyl derivatives. The physical data quoted have been taken from the first or at most the first two references cited, the remaining references having been arranged in numerical order. An asterisk indicates that the value for the melting point or boiling point has been corrected. 

In early studies into the use of the dithiasuccinoyl (Dts) primary amine protecting group, the desired (V-alkylated derivatives (6) were prepared from the reaction between O-ethyl-AAalkyl (or aryl) thiocarbamates (9) and cblorocarbonylsulfenyl chloride (5) (eq9). ... 

There is a wide variety of dyes unique to the field of hair coloring. Successive V-alkyl-ation 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 V-alkyl derivatives do not have good dyeing properties, patent activity has concentrated on the superior V-hydroxyalkyl derivatives of nitrophenylenediamines, some of which have commercial use (30). A series of patents also have been issued on substituted water-soluble azo and anthraquinone dyes bearing quaternary ammonium groups (31). 

The preparation of diazo hydrocarbons is generally carried out by the alkaline decomposition of Af-nitroso-./V-alkyl derivatives such as the iV-nitroso derivatives of sulfonamides, amides, and phthal-amides, urethanes, ureas, nitroguanidines and /7-alkylaminoisobutyl ketones. Of these, the decompositions of 7V -alkyl- -nitroso-p-toluenesulfonamide and of bis (iV-methyl-A nitroso)terephthalamide... 

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