Dimethyl amides

Toluene-p-sulphonamide can be similarly converted into the dimethyl-amide, but the methylation now occurs in two definite stages. First the sulphonamide dissolves in the sodium hydroxide to form the mono-sodium salt (see p. 252), which then reacts with the dimethyl sulphate to give the mono-... 

Analog erhalt man durch Reduktion mit Kaliumboranat aus l-Methyl-2-phenyl-indo-lyl-(3)-glyoxylsaure-dimethylamid 1-Methyl-2-phenyl-indolyl-(3)-glykolsaure-dimethyl-amid (F 137-1390)3. 

N-methyl-anilid)-Nickelsalz 344 -S-[4-methyl-penten-(2- bzw. 3) -ylester]-dimethyl-amid 344... 

ETHYLENE GLYCOL ETHYL MERCAPTAN DIMETHYL SULPHIDE ETHYL AMINE DIMETHYL AMIDE MONOETHANOLAMINE ETHYLENEDIAMINE ACRYLONITRILE PROPADIENE METHYL ACETYLENE ACROLEIN ACRYLIC ACID VINYL FORMATE ALLYL CHLORIDE 1 2 3-TRICHLOROPROPANE PROPIONITRILE CYCLOPROPANE PROPYLENE 1 2-DICHLOROPROPANE ACETONE ALLYL ALCOHOL PROPIONALDEHYDE PROPYLENE OXIDE VINYL METHYL ETHER PROPIONIC ACID ETHYL FORMATE METHYL ACETATE PROPYL CHLORIDE ISOPROPYL CHLORIDE PROPANE... 

A similar sequence starting with the acylation product (76) from metachlorophenylacetonitrile gives the halogenated tricyclic ketone 83. Condensation of that intermediate with ethyl bromoacetate in the presence of zinc (Reformatsky reaction) gives the hydroxyester 84. This product is then in turn dehydrated under acid conditions (85), saponified to the corresponding acid (86), and converted to the dimethyl-amide (87) by way of the acid chloride. The amide function is then reduced to the amine (88) with lithium aluminum hydride catalytic hydrogenation of the exocyclic double bond completes the synthesis of closiramine (89). This compound also exhibits antihistaminic activity. 

The last group of aliphatic amides to be discussed are the tertiary amides, which, by definition, carry two alkyl substituents on the N-atom. Investigations of their chemical stability have disclosed a surprising difference between tertiary and secondary amides, since the rate of acid-catalyzed hydrolysis of N,N-dimethyl amides is higher than that of A-methyl amides. If steric fac-... 

O-Protonated cations of eimides in concentrated and anhydrous acids are now well characterized by nmr spectroscopy. O-Protonated cations of N,N-dimethyl amides are most easily observed, even in 72% perchloric acid which has a water activity of about 10 , because for tertiary amides the N-protonated forms is relatively less stabilized by hydration (Liler, 1972a). O-Protonated cations of N-alkyl amides show considerable exchange of NH-protons with the solvent in 72% perchloric acid owing to the intervention of the N-protonated form. For primary amides (acetamide), however, O-protonated cations are not observable in that solvent (Liler, 1972b),... 

Better reagents than lithium aluminum hydride alone are its alkoxy derivatives, especially di- and triethoxyaluminohydrides prepared in situ from lithium aluminum hydride and ethanol in ethereal solutions. The best of all, lithium triethoxyaluminohydride, gave higher yields than its trimethoxy and tris(/er/-butoxy) analogs. When an equimolar quantity of this reagent was added to an ethereal solution of a tertiary amide derived from dimethylamine, diethylamine, W-methylaniline, piperidine, pyrrolidine, aziridine or pyrrole, and the mixture was allowed to react at 0° for 1-1.5 hours aldehydes were isolated in 46-92% yields [95,1107], The reaction proved unsuccessful for the preparation of crotonaldehyde and cinnamaldehyde from the corresponding dimethyl amides [95]. 

Early workers noted that electrochemical oxidation of N,N-dimethyl-amides in acetic acid gives the a-acetoxy compound [101]. Oxidation in acetic acid of amides derived from piperidine and pyrroUdine proceeds differently to yield a mixture of stereoisomers of the a,P-diacetoxy and p-acetoxy-a-hydroxy compounds [125]. 

Af,A-Dimethyl amides are susceptible to attack at C=0, but can be successfully ortholithiated if kept cold. Keck and coworkers used successive ortholithiations of 23 in a route towards pancratistatin (Scheme 12) . (Park and Danishefsky s similar route using Af,A-diethylamides suffered from difficulties removing the amide group.)... 

Li-CH-(S ) 1 C0-N(CH3)2 Ar 0 1 II 02N CH2-CH-CH-C-NfCH3)2 s- s 3- (2,5-Dimethoxy-4-methyl-phenyl)-2-( 1,3-dithian-2-yl) -4-nitro-butansdure-dimethyl-amid 88 137-138... 

Azidoformic Acid Dimethylamide. See under Formic Acid Dimethyl Amide and Beil 4,... 

As shown in Table 9 acetylation of polysarcosine destroys the effect and the addition of such a polymer to phenylalanine dimethyl amide only slightly accelerates the process. (5) No effect is observed when sarcosine NCA is block-polymerised in poly-D.L-phenylalanine. 

The concept of in situ liberation of carbon monoxide would be even more attractive if a metal-free material could serve as the carbon monoxide source. In the ideal carbonylation method, the organic solvent itself could be exploited for controlled generation of carbon monoxide. In 2002, Wan et al. addressed this issue and developed a microwave-promoted carbamoylation process based on the commonly used solvent dimethylformamide (DMF) as the carbon monoxide precursor75. Firstly, it was discovered that aryl dimethyl amides were accessible from the corresponding bromides in the presence of a nucleophilic catalyst, imidazole (Scheme 2.34). Secondly, tertiary benzamides other than dimethylamides were synthesised by addition of 3 equiv of an external amine (Scheme 2.34). 

This is because the conjugate acid of tetramethylguanidine has much greater resonance stabilization than the IV,IV-dimethyl amide (more forms and equivalent forms.)... 

The amide nitrogen bears two methyl groups. We designate this as an A,A-dimethyl amide. 

Chlorbutiric acid dimethyl amide are dissolved in absolute benzene and heated to 110°C with propylamine in the autoclave. After cooling the propylamine hydrochloride is filtered off, then the benzene solution is treated with water and freed from any dissolved propylamine hydrochloride by means of potassium lye. After distillation of the benzene the 2-propylaminobutyric acid dimethyl amide is rectified in vacuum. 

Propylaminobutyric acid dimethyl amide is dissolved in benzene and while cooling, crotonic acid chloride is added and mixed. Then, reaction mixture is filtered and freed from benzene to give 2-(N-propyl-crotonylamido)butyric acid dimethyl amide, melting point 128°-130°C. 

A related reaction which leads to the direct introduction of an acyl group into the pyridine nucleus involves the reaction of benzoate esters or dimethyl amides with pyridine in the presence of magnesium or aluminum and mercury and mercuric chloride.308 When aluminum is used in the reaction of ethyl benzoate with pyridine, 2-benzoyl-(23.9%) and 4-benzoylpyridine (6.4%) are obtained. Under these... 

One of the characteristics of reactions involving benzyne intermediates is that the nucleophile can bond to the same carbon to which the leaving group was bonded, or it can bond to the carbon adjacent to the one to which the leaving group was bonded. This often results in the formation of isomeric products when substituted aromatic halides are used. For example, the reaction of yo-bromotoluene with sodium dimethyl-amide in dimethylamine as the solvent gives a 50 50 mixture of the meta and para... 

Cl-CH2)2P cl (HjCJjNH Bis-[chlormethyl phosphinsaure-dimethyl- amid 55 (Schmp. 6 1°) 758... 

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