Dimethyl formamide derivatives

Amino-pyridazines and -pyridazinones react with monomethyl- or iV,A-dimethyl-formamide and other aliphatic amides in the presence of phosphorus trichloride, thionyl chloride, phosgene or benzenesuUonyl chloride to give mono- or di-alkylaminomethyl-eneamino derivatives. The same compounds can be prepared conveniently with A,iV-dimethylformamide dimethyl acetal in high yield (Scheme 50). 

Furfuryl dimethyl amine is first produced. This may conveniently be accomplished by employing the Leuckart synthesis known to those skilled in the art, which involves the use of an aldehyde or a ketone, and formate of ammonia or an amine, or corresponding formamide derived by dehydration of formate of ammonia or an amine. 

The benzo analogue 684 of [1,2,4]triazino[3,2-6]thiazoles was prepared (88LA1089) by heating triazine derivative 632 with 2,4-dinitrochloroben-zene or picryl chloride in N,N-dimethyl formamide (Scheme 143). 

With hydrobromic acid and potassium bromate 7-methylxanthine (159 X = H) gave the 2-bromo derivative (159 X = Br) in 83% yield (84CHE924). Conversion of a variety of 2-substituted-6-trifluoromethyl-purines into the anions, followed by treatment with NBS in hot dimethyl-formamide, gave 20-60% yields of 2-bromo derivatives (90JHC1505). 

A second, more convenient approach was tried starting with dicyclopropyla-cetylene 56 [15-17] which, after deprotonation with tert-butyllithium at both propargylic positions, yielded the bisaldehyde 57 upon treatment with dimethyl-formamide. The latter was converted to the bis(dibromoethenyl) derivative 58, and this in turn to the dibromotriyne 59 by standard methods (Scheme 11) [18]. The dibromide 59 was coupled with the ethynylcyclopropylheterocuprate 50 to give the terminally bis-protected pentayne 60. 

Ring D inversion seems to be a crucial step in biogenetic transformations of protoberberines to related alkaloids such as rhoeadine, retroprotoberberine, spirobenzylisoquinoline, and indenobenzazepine alkaloids. 8,14-Cyclober-bin-13-ol 478 derived from berberine (15) was successively treated with ethyl chloroformate, silver nitrate, and pyridinium dichromate (PDC) in dimethyl-formamide to give the keto oxazolidinone 479 (Scheme 98). Heating of 479 with 10% aqueous sodium hydroxide in ethanol effected hydrolysis, retro-aldol reaction, cyclization, and dehydration to provide successfully the... 

Transition metal complexes have been used in a number of reactions leading to the direct synthesis of pyridine derivatives from acyclic compounds and from other heterocycles. It is pertinent also to describe two methods that have been employed to prepare difficultly accessible 3-alkyl-, 3-formyl-, and 3-acylpyridines. By elaborating on reported194,195 procedures used in aromatic reactions, it is possible to convert 3-bromopyridines to products containing a 3-oxoalkyl function196 (Scheme 129). A minor problem in this simple catalytic process is caused by the formation in some cases of 2-substituted pyridines but this is minimized by using dimethyl-formamide as the solvent.196... 

The reaction of sucrose with a combination of 2,2-dimethoxy-propane-N,N-dimethylformamide-p-toluenesulfonic acid has been exploited to give various, interesting, cyclic acetal derivatives.32,83-85 This combination of reagents for acetonation is known to give strained, and otherwise inaccessible, acetals of monosaccharides.86-89 Treatment of sucrose with 2,2-dimethoxypropane in N,N-dimethyl-formamide in the presence of a catalytic proportion of p-toluenesul-fonic acid for 80 min at room temperature afforded a mixture containing 4,6-O-isopropylidenesucrose, 2,1 4,6-di-O-isopropyli-... 

Duchenne muscular dystrophy dimethyl formamide 5,5-dimethyl-1 -pyrroline-1 -oxide deoxynucleic acid diphenylene iodonium endothelium-derived relaxing factor epidermal growth factor early growth phase response gene ethyleneglycol- bis- (p- aminoethyl)-N,N,N, N -tetraacetic acid... 

The salts (294) (Section VII, J, 1) are useful intermediates for the preparation of other meso-ionic systems by reaction with appropriate nucleophiles. Thus, reaction with sodium sulfide in dimethyl formamide yields the l,2,3,4-tetrazole-5-thiones (295), a new class of meso-ionic heterocycle. The 1,3-diphenyl derivative (295, R = = Ph) has a... 

Mass spectrometry and gas-liquid chromatography showed 3-formylthieno[2,3-6]thiophene (0.2%) in the crude product from While diformyl derivatives were not observed from 2 with two equivalents of DMF, small quantities of the diformyl derivatives were detected by mass spectrometry in the case of thienothiophene l. Italian researchers obtained 2,S-diformylthieno[3,2-Mthiophene by the action of n-butyllithium and dimethyl formamide on 2,5-dibromothieno[3,2-2>]-thiophene. ... 

In this paper a generalized approach is presented to the derivation of H-H-S equations for multispecies polymers created by addition polymerization across single double bonds in the monomers. The special cases of copolymers and terpolymers are derived. This development is combined with experimental results to evaluate the numerical parameters in the equations for poly(styrene-acrylonitrile ) (SAN) in three separate solvents and for poly(styrene-maleic anhydride-methyl methacrylate) (S/HA/MM) in a single solvent. The three solvents in the case of SAN are dimethyl formamide (DMF), tetrahydrofuran (THF), and methyl ethyl ketone (MEK) and the solvent for S/HA/HH is HER. 

R = CH2CH—CH2/, dimethyl formamide with the bromide to prepare 29 (R = CH2C=CH), and tetrahydrofuran to prepare the 9-(3-dimethyl-aminopropyl) derivatives of the four isomeric nitrocarbazoles using the tosylates as alkylating agents. ... 

In the introduction of exp. 3 it is mentioned that lithiated acetylenes react very slowly at 70 C with dimethylfonnamide. However, lithiated benzene derivatives in most cases add very quicldy to DMF at these low temperatures. This difference in basicity may explain the specific reaction of the ortho-aryl negative center in dilithiated phenylacetylene with dimethyl-formamide. 

It has been found32 that treatment of methyl 4,6-dichloro-4,6-dideoxy-a-D-gaIac-topyranoside 2,3-di(chlorosulfate) (8) with sodium bromide in N,N-dimethyl-formamide at room temperature affords methyl 4,6-dichloro-4,6-dideoxy-o -D-galactopyranoside and its 2- and 3-mono(chlorosulfate) derivatives. These three products were also formed, in addition to a mono(azidosulfate) derivative, when 8 was treated with sodium azide in N,N-dimethylformamide at room temperature. 

A pressure vessel containing a tyrosine derivative dissolved in dimethyl formamide containing 2 (2 eq) was treated with the dropwise addition of ethyl bromide (1.1 eq) and then heated to 60°C for 30-minute intervals while being monitored by thin-layer chromatography (TLC). The reaction was then quenched with water and the aqueous layer extracted and then dried over Na2S04. The mixture was filtered, concentrated, and the product isolated. 

Several attempts to prepare typical alcohol derivatives of [Cr(HO-A)2]-were unsuccessful these include Schotten-Bauman conditions (acetyl chloride in chloroform shaken with cold, aqueous alkaline solution of complex), refluxing in acetyl chloride, in glacial acetic acid, acetyl chloride in hot dimethyl formamide, acetyl chloride and pyridine in acetonitrile, and acetic anhydride in acetonitrile. The failure of refluxing acetyl chloride to effect acetylation brings to mind the work of Keller and Edwards (4) the acetyl chloride system is completely heterogeneous and consequently not conducive to reaction. However, even the homogeneous reaction of [Cr(HO-A)2] — with acetyl chloride in acetonitrile failed to give a measurable quantity of the diester. 

---