Gem-dinitroalkanes

Aliphatic nitroalkanes can be categorized into six basic groups primary, secondary and tertiary nitroalkanes, terminal and internal gem-dinitroalkanes, and trinitromethyl compounds. Primary and secondary nitroalkanes, and terminal gem-dinitroalkanes, have acidic protons and find particular use in condensation reactions for the synthesis of more complex and... 

A range of primary and secondary nitroalkanes and their derivatives have been converted to the corresponding gem-dinitroalkanes via oxidative nitration, including the conversion of nitroethane, 1-nitropropane, 2-nitropropane and 2-nitro-1,3-propanediol to 1,1-dinitroethane (78 %), 1,1-dinitropropane (86 %), 2,2-dinitropropane (93 %) and 2,2-dinitro-1,3-propanediol (77 %) respectively. The silver nitrate used in these reactions can be recovered quantitatively on a laboratory scale and this has led to a study where oxidative nitration has been considered for the large-scale production of 2,2-dinitropropanol (25) from the nitroethane (22). ... 

Oxidative nitration has a number of advantages over pre-existing routes to gem-dinitroalkanes, including ... 

Good yields of internal gem-dinitroalkanes are attainable, whereas the Ter Meer reaction fails for the synthesis of this class of compounds. 

Oxidative nitration is a one step process from nitroalkane to gem- dinitroalkane, whereas the Ter Meer reaction requires two steps (initial halogenation followed by halide displacement with nitrite anion). 

Nielsen and Bedford synthesized gem-dinitroalkanes (147) from the Michael addition of organolithium reagents to a-nitroalkenes (146) followed by quenching of the resulting nitronate anion with tetranitromethane. The same reaction using alkoxides as bases provides P-alkoxy-gem-dinitroalkanes (148). ... 

The use of primary nitramines in Mannich reactions is an important route to numerous secondary nitramines. However, a far more common route to such nitramines involves the Mannich condensation of a terminal gem-dinitroalkane, formaldehyde, and an amine, followed by IV-nitration of the resulting polynitroalkylamine. The preformed methylol derivative of the gem-dinitroalkane is often used in these reactions and so formaldehyde can be omitted. This route has been used to synthesize explosives like (92) and (209). ... 

Preparation of gem-Dinitroalkanes. A methanolic solution of alkali metal hydroxide (Li, Na, or K) was treated with 10% excess nitroalkane and stirred for 30 minutes. The solution was evaporated to dryness in vacuo, and the alkali metal alkyl nitronate was aned over phosphorus pentoxide at reduced pressure (0.1 mm.) for 24 hours. (Caution nitronate salts may be shock sensitive and have been known to explode after prolonged storage.) A slurry of 3.3 grams (0.02 mole) of lithium 1-nitro-cyclohexane in 50 ml. of acetonitrile was cooled to —40°C., and 2.7 grams (0.02 mole) of nitronium tetrafluoroborate were slowly added. The reaction was not exothermic, and the reaction mixture turned brilliant blue upon adding nitronium tetrafluoroborate. The reaction mixture was stirred for 2 hours at —30° to —40°C., then filtered to give a quantitative yield of lithium tetrafluoroborate. The filtrate was quenched into 100... 

Nitration. The synthesis of gem-dinitroalkanes by reaction of nitronate anions with the combined salts is efficient. 

Nitric acid (70 %) or the mixture of nitric acid and sulfuric acid or other mixed acids with catalytic function can nitrate secondary nitroalkanes directly into gem-inal dinitroalkane [8]. With the sodium alkoxide and tetranitromethane, primary nitroalkanes can be nitrated into dinitroalkanes and trinitroalkanes [9]. In a neutral or basic solvent, primary, secondary nitroalkane salts can be nitrated, step by step, into gem-dinitroalkanes by silver nitrate and sodium nitrite [10]. Alkali metal salts of aryl nitroalkanes can be nitrated, step by step, into dinitroalkanes and trinitroalkanes by dinitrogen tetroxide [11]. 

Substitution reactions of simple sulphenyl chlorides with features of additional interest include 1,3-dithiolan formation by reaction of 1,2-disulphenyl chlorides at a methylene group o to —CHO formation of cK-chloro- -keto-sulphides from sulphenyl chlorides and adducts of phosphines with 1,2-dicarbonyl compounds free-radical substitution of saturated alkanes by C6CI5SCI and synthesis of aa-dinitroalkyl sulphides by treatment of gem-dinitroalkanes with sulphenyl chlorides in the presence of base. ... 

Reduction of the double bond Pt>lynicri/.ation Nilroacctyicncs Ptdynitro aliphatic compounds Nitration of hydrocarbons Substitution of halogen Electrolytic methods Addition reaction Michael addition Diels-Alder addithm Oxidative dimerizatum a, to-Dinitroalkanes gem-Dinitroalkancs Iriniiromclhane (nitroform) derivatives Properties of nitroform Manufacture of nitroform... 

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