N-Nitroureas

Standard techniques are used to substitute on nitrogen. Allyl and substituted allyl halides substitute directly, whereas alkyl and CPM functions are best introduced via the acyl halide followed by LAH reduction.(61) Reaction of norbenzomorphans with N-nitrourea or with urea, acetic acid, and HC1 affords N-carbamoylbenzomorphans.(65,66) N-Arylamidinobenzomorphans have also been reported.(67)... 

NITROUREA see NMQ500 N-NITROUREA see NMQ500 NITROUS ACID see NMROOO... 

A fused heterocyclic compound (146) distantly related to the antiinflammatory agent cintazone (Chapter 12), which itself can be viewed as a cyclized derivative of phenylbutazone, retains the activity of the prototype, in the synthesis of 146, reaction of the nitroaniline 139 with phosgene gives intermediate 140, which is then reacted with ammonia to afford the substituted urea (141). Cyclization of the ortho nitrourea function by means of sodium hydroxide leads to the N-oxide (142) this last reaction represents... 

Nitro-3(2,4-dinitrophenyl) urea Nitroguanidine N-Nitromethylamine Nitrourea... 

N-w-heptylurea has been prepared by the action of nitrourea on w-heptylamine.6... 

The nitrile group in 82 has been transformed into other versatile functional groups, and the derivatives so obtained have been used in the synthesis of various naturally occurring C-nucleosides and their analogs. Reduction of 82 with lithium aluminum hydride gave the amine 90 which was, in turn, transformed84 into the ureido and N-ni-troso derivatives (91-93) by treatment with nitrourea, followed by benzylation, and nitrosation.85 The diazo derivative 94, obtained by treatment of 93 with alcoholic potassium hydroxide, was a key intermediate in the synthesis of formycin B and oxoformycin B (see Section III,2,a,b). 

The synthesis, properties and potential uses of high performance IV-nitroureas and N,N -dinitroureas are discussed in more detail in Chapter 6. 

Davis studied the dehydration of urea nitrates as a route to iV-nitroureas. The nitrate salt of iV-methylurea undergoes dehydration-rearrangement on treatment with concentrated sulfuric acid to give Af-nitro-A -methylurea in 42 % yield. In this compound the nitro and methyl groups are attached to the same nitrogen and so its hydrolysis can provide a route to methylnitramine. In contrast, the nitrate salts of ethyl, n-propyl, n-butyl and n-amyl ureas, give iV-nitro-A -ethylurea (49 %), A -nitro-A -propylurea (60 %), iV-nitro-iV -butylurea (67 %) and iV-nitro-A -amylurea (67 %), respectively, on treatment with concentrated sulfuric acid. 

V-nitramines too were reduced to disubstituted hydrazines. Electrolysis in 10% sulfuric acid over copper or lead cathodes reduced AT-nitrodimethylamine to. /V,JV-dimethylhydrazine (yield 69%), 7V-nitro-JV-methylaniline to N-methyl-JV-phenylhydrazine (yield 54%), W-nitropiperidine to JV,A -penta-methylenehydrazine (yield 52%) [734], and nitrourea to semicarbazide (yield 61-69%) [755]. 

Nitro-3-(2,4-dinitrophenyl)urea, 2705 Nitroguanidine, 0482 N-Nitromethanimine, 0408 N-Nitromethylamine, 0478 Nitrourea, 0460... 

Helf (Ref 6) investigated ten hew materials as flash smoke suppressants in proplnts. Guanylurea Nitrate was the most promising compd with regard to physical chemical props, stability, and 0 balance. Guanylnitro Urea was unsuitable for proplnts contg NG. Carbohydrazide-N-carboxyamide Carbohy-drazide-N,N -dicarboxyamide showed desirable promise but depended on a special starting material. Ammonium Nitrourea, Diammonium -methylene-bis-(nitrosohydroxylamine) ... 

R5C2XH2)2N.CO.NH2, nw 144.21, N 19.43%, ndls (from petr eth), mp 76° v sol in w. It can be prepd from reaction of dipropylamine nitrourea in water. It forms cryst salts, such as Nitrate, OxaLate St Picrate (Ref 2)... 

Semicarbazide Hydrochloride (Amidourea hydrochloride). CHsON3.HC1 mw 111.52 N 37.69% OB to C02 —57.39% colorl prisms or snow-white crysts mp 173°, 175—77° (sep values, decompn). V sol in w sol in dQ ethanol insol in absol ethanol and eth, Prepn is by electrolytic redn of nitrourea with cathodes of Cu, Ni, Pb and Hg in hydrochloric acid soln (Refs 1 7). CA Registry No [56341-7]. The hydrochloride is used in rubber-Amm perchlorate solid proplnts in amounts of from 0.1 to 10% as a burning rate depressant. At 300psi chamber press the hydrochloride is reported to effect a 31% depression in the burning rate (Ref 6)... 

Nitrourea, 10,112 Nonamethylene glycol, 14, 22 5-Nonanol, 15,11 n-NoNOic acid, 16, 60... 

Nitrourea forms colorless to whitish plate like crystals that begin to decompose when heated to 158 Celsius. The crystals are soluble in alcohol, acetic acid, and acetone—they are insoluble in cold water. The nitrate and perchlorate salts of nitrourea are prepared by treati ng nitrourea with the correspondi ng acids—the nitrate and perchl orate salts are used i n f i reworks, and a variety of pyrotechnic compositions. Nitrourea has limited use in explosives due to its lack of explosives power, but it can be used in rocket propellants and gunpowders. Nitrourea isalso commonly used in making other explosives. It requiresa... 

Nitrourea is decomposed quantitatively into cyanic acid and nitrous oxide when heated in aqueous solution. If primary or secondary amines are present, the products are alkylureas or N,N-diaIkylureas, respectively.Alcohol is used as a solvent for amines which are only slightly soluble In water. The yields in general are excellent (70-98%), and the reaction is preferred to the exchange with urea described above. Alkanolamines give hydroxyalkylureas in 85-95% yields." Nitrourea is conveniently prepared in 90% yield from urea nitrate."... 

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