Dimethyl-amine oxalate

Mixtures of 3//-azepines are also formed from l,2-dimethyl-4-nitrobenzene, which in diethyl-amine yields A,./V-diethyl-5,6-dimethyl-3//-a7cpin-2-amine (9%) and AfN-diethyl-4,5-dimeth-yl-3f/-azcpin-2-aminc (22% oxalate mp 119-120°C).66 Likewise, 2,4-dimethyl-l-nitrobenzene furnishes a mixture of /V.A-diethyl-5,7-dimethyl-3//-azepin-2-amine (7% oxalate mp 140-141UC) and /V,A-diethyl-3,5-dimethyl-3//-azepin-2-amine (2% oxalate mp 85-86 C). The symmetrically substituted l,3-dimethyl-5-nitrobenzene, as expected, yields only (V.tV-diethyl-4,6-dimethyl-3//-azepin-2-amine (46% bp 96 99 (2/1.3 Torr). 

A very useful three-carbon olefin is acrolein dimethyl acetal (5). Acrolein itself cannot be used because it polymerizes and/or reacts with amines under the normal reaction conditions. With piperidine or morpholine as the base, acrolein acetals react in good yield with a wide variety of vinylic bromides to give dienal acetals and/or ami-noenal acetals. These product mixtures, after being treated with excess aqueous oxalic acid and being steam distilled, yield E,E-conjugated dienals, usually in good yields. Methacrolein acetals and 3-buten-2-one ethylene ketal also react well, but the crotonaldehyde acetals do not. 

Related reactions include the formation of the 2-cyano compounds (190) when 1,2-dimethyl-5-nitroimidazole is heated with nitrosyl chloride or an AT-oxide, and when 2-methyl-l-(o-nitrophenyl)imidazoles (191) cyclize under the influence of iron(II) oxalate (Scheme 98) (74JCS(P1)1970). The last reaction product is contaminated by a large amount of amine reduction product ( 64%) but there is also some cyclization with the 4-methyl isomer of (191). In the presence of trimethylamine, 2-cyanomethylbenzimidazole condenses with acetone to give the unsaturated derivative (192 Scheme 99) (77CPB3087). Neither 2-methylimidazole nor 2-methylbenzimidazole reacts with formamide in the presence of phosphoryl chloride. 

Dehydration Alumina. Alumina-Pyridine-Diluent (sand). Dicyclohexylcarbodiimide. N,N-Diethyl-l-propynylamine. Dimethyl sulfoxide. Diphenylcarbodiimide. Iodine. Methoxya-cetylene. Oxalic acid. Phenylcyanate. Phosphorus pentoxide-t-Amine. Phosphoryl chloride-Phosphoric acid-Phosphorus pentoxide. Phosphoryl chloride-Pyridine. Thionyl chloride. 

After addition of monomethyd methylphosphonite to methyl acrylate, the product is converted in a Claisen reaction with dimethyl oxalate into the corresponding a-keto-acid, which is then subjected to a reductive amination. [14]... 

Diethylamine Miscible Dieth ether Miscible bis-(2.ethylhexyl)amine 0.7 Diethyl sulfide MlKible Di-isobutyl carbinol Miscible Di-isobutylene 3.3 <0.6% DMSO soluble in di-isobutylei>e) Disopropyl ether 11 Dimethyl ether 4.4 Dimethyl formamide Miscible Morpholine Naphthalene Neoprene Nitrobenzene Oleic acid Ouricuri wax Oxalic add Palmitic acid Paraffin Paraformaldehyde Miscible 40 Insol. Miscible Misdble 38 100 Insoluble Insoluble Miscible Inso 1 Slightly soluble... 

Oxalic ester synthesis—Enolesters from ketones. 6 g. dl-zl5,14-3.Ethylenedioxy-lly ,18-oxido-16-oxo-18-tetrahydropyranyloxyandrostadiene and dimethyl oxalate in benzene added dropwise to NaH in oil (Metal Hydrides, Inc., Beverly, Mass., USA) and benzene, stirred 48 hrs. at 30° in a slow Ng-stream, the crude product dissolved in benzene, and allowed to stand at room temp, overnight with acetic anhydride and pyridine 6.61 g. methyl dl-J5,14,17(20)-3-ethylene-dioxy-1 ly, 18- oxid o-16- oxo-18- tetrahydropyranyloxy - 20 - acetoxypregnatrien-21-ate, 6 g. suspended in an ice-cold 10 1 mixture of morpholine and water, stirred 3-4 hrs. until a clear soln. results, allowed to stand 24 hrs. at ca. 10°, evaporated almost to dryness at 35-40°/0.05 mm., a mixture of benzene and ether then pyridine added, ice-cooled, acetic anhydride added, and allowed to stand 24 hrs. at room temp. 5.55 g. dl-j5,14,17(20)-3-ethylenedioxy-ll, 18-oxido-16-oxo-18-tetrahydropyranyloxy-20-acetoxypregnatrien-21-ic acid morpholide.—Morpholine is preferred to other sec. amines because of its good solvent properties (cf. Synth. Meth. lA, 87). Use of anhydrous amines caused decomposition. K. Heus-ler, P. Wieland, and A. Wettstein, Helv. A2, 1586 (1959). 

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