Aziridines sodium hydride

Aziridinylbenzaldoxime 340, formed from the reaction of a hydroximoyl chloride with aziridine 339 (Scheme 56), reacts with HG1 to form the chloroalkyl-substituted amidoxime 341. Reaction with sodium hydride affects ring closure to give the 3-aryl-4,5-dihydro-5-isopropyl-l,2,4-oxadiazoles 343. This latter reaction is proposed to proceed... 

Treatment of vV-methoxy-5-methyl-5//-dibenzo[a,d]cycloheptene-5-amine (9) with sodium hydride in tetrahydrofuran/dimethyl sulfoxide afforded the expected cyclization product, which in turn, by increasing the temperature, was converted to the aziridine by internal displacement of the N-methoxy group48. ... 

The oxazolidone tosylate 101 with sodium hydride in benzene at 55°C gives the aziridine 102 (48%). This aziridine reacts with sodium p-cresolate in hexamethylphosphoramide to yield two products. Attack of the anion at C5 of the aziridine 102 forms the oxazinone 103, while attack at C6 leads to the oxazolidinone 104. 

The aziridine derivative 117, a photochemical valence tautomerization product of berberinephenolbetaine, was also converted into the benzindan-oazepines by regioselective C-14—N bond cleavage (Scheme 24)." The treatment of 117 with p-toluenesulfonic acid in benzene under reflux gave rise to the benzindenoazepine 118 whose N-methylation with dimethyl sulfate in HMPA in the presence of sodium hydride afforded the n-methyl derivative 119." Since 119 has already been converted" to ( )-c -alpini-genine (120) and ( )-ds-alpinine (121), this synthesis constitutes a formal synthesis of these alkaloids. 

When aziridin-2-yl phenyl ketone tosylhydrazones 16 were treated with boron trifluoride -diethyl ether complex, l,2,5,6-tetrahydro-l,2,3-triazines 15 were isolated.362 Treatment of 16 with sodium hydride afforded l,6-dihydro-l,2,3-triazines 17.363... 

Aziridination of a-trifluoromethyl-substituted acrylates such as 137 can be accomplished with ethyl nosyloxycarbamate. With a weak base such as calcium oxide, a Michael adduct is obtained (138), but with sodium hydride Michael addition is followed by cychzation with extrusion of nosylate ion to give 139. ... 

Another interesting stereospecific transformation is the conversion of enantiomerically pure a-Li alkyl sulfoxides to vicinal chloroamines (eq 29). The nonoxidative chloro-Pummerer rearrangement was proposed as the mechanism. The final products can be converted to the corresponding aziridines by treatment with sodium borohydride followed by sodium hydride. 

Aziridination of unsaturated ketones can be achieved directly using sodium hydride in conjunction with iV,)V -diammo-l,4-diazoniabicyclo[2.2.2]octane dinitrate (eq 41). This reaction proceeds through a nitrogen-nitrogen ylide. The yUde undergoes Michael addition followed by cyclization of the resulting enolate and expulsion of the tertiary amine. 

A novel approach to aziridines employs the use of sodium hydride in DMSO with dichloroazetidines (eq 51). The choice of DMSO is critical in obtaining the desired product. This transformation is proposed to go through a highly strained 2-azetine. 

Stable aziridinyl carbanions (648) have been prepared by treating the corresponding aziridine with sodium hydride in HMPA. ... 

Sodium hydride (dimethyl sulfoxide Aziridines from 2-halogenamines... 

Few papers have been published on heterocyclic enaminonitriles. A recent addition reports on their preparation and reactions. Thus, in the presence of sodium hydride, aziridines react with malononitrile to form dihydropyrroles (99). 

Sodium hydride I dimethyl sulfoxide Ring closure with sulfonium ylids Aziridine ring from azomethines... 

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