3.4- Dimethyl-l-nitrobenzene

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). 

Chloro-3- [(1 -ethoxycarbonyl-1 -methylethyl)amino] -4-nitrobenzene (61) gave 6-chloro-3,3-dimethyl-3,4-dihydro-2(l //)-quinoxalinone (62) (TiCl3, AcONa, HeO-MeOH, 20°C, 2.5 h >95%).1042... 

M,N -Dimethy 1-2,4,6-trinitro-N,N dinitro-phenylenedi amine N N -Bistmethyl) -N,N -d initramino-2,4,6-tri nitrobenzene 1,3-Bis(methylnitramino)-2,4,6 trinitrobenzene or N,Ni-Dimethyl-H,N,2,4,6-pentanitropHenyl-ene-1,3-diamine called by the British Ditetryl. This must not be confused with American Ditetryl, called.hy the British Octyl, which is l,2-Bis(2(4,6,-trinitro-anilino)-ethane (See Vo I 2 of Encycl, p... 

Dimethyl-3-nitroaniIine l,3-Dimethyl-2-nitrobenzene very good yield 150... 

Dimethyl-6-nitro aniline l,3-Dimethyl-5-nitrobenzene (62%, pure) 151... 

In contrast, dipolar aprotic solvents possess large relative permittivities (sr > 15), sizeable dipole moments p > 8.3 10 ° Cm = 2.5 D), and average C.f values of 0.3 to 0.5. These solvents do not act as hydrogen-bond donors since their C—H bonds are not sufficiently polarized. However, they are usually good EPD solvents and hence cation sol-vators due to the presence of lone electron pairs. Among the most important dipolar aprotic solvents are acetone, acetonitrile [75], benzonitrile, A,A-dimethylacetamide [76, 77], A,A-dimethylformamide [76-78], dimethylsulfone [79], dimethyl sulfoxide [80-84], hex-amethylphosphoric triamide [85], 1-methylpyrrolidin-2-one [86], nitrobenzene, nitro-methane [87], cyclic carbonates such as propylene carbonate (4-methyl-l,3-dioxol-2-one) [88], sulfolane (tetrahydrothiophene-1,1-dioxide) [89, 90, 90a], 1,1,3,3-tetramethylurea [91, 91a] and tetrasubstituted cyclic ureas such as 3,4,5,6-tetrahydro-l,3-dimethyl-pyr-imidin-2-(l//)-one (dimethyl propylene urea, DMPU) [133]. The latter is a suitable substitute for the carcinogenic hexamethylphosphoric triamide cf. Table A-14) [134]. 

EHDNPB, l-(2 -ethylhexyloxy)-2,5-dimethyl-4-(4"-nitrophenylazo)benzene stilbene 3-DCTA, N,N-bis[4-(9H-carbazol-9-yl)phenyl]-4-[3-[4-[2-(4 nitropheny])ethenyl]phenoxy]propoxy]-benzenamine DOP, dioctyl phthalate bisA-NAS, poly[4,4 -isopropylidenediphenol-co-4-nitro-4 -bis(2,3-epoxypropyl)aminostilbene HONB, 4-(hexyloxy)nitrobenzene PBPES, poly[(4-n-butoxyphenyl)-ethyloilane] other abbreviations are defined in the text and Figures, —, data not available. 

Among the chemicals that are only now slowly attracting attention are nitro-aromatic compounds and fiuorinated organics. Nitrobenzene in the ng/1 range and l-chloro-2-nitrobenzene in one order of magnitude lower concentrations are widely distributed in the German Bight, and musk xylene (l-fert-butyl-3,5-dimethyl-2,4,6-trinitrobenzene) and musk ketone (l-fert-butyl-3,5-dimethyl-... 

Electrochemical reduction of the trithiapentalenes (804 R = H, Me, or Ph) yields the corresponding radical anions, which are converted into the thiapyran-thiones (807)/" ° 1-Phenyl-6,6a-dithia-l,2-diazapentalene (808) is nitrated mainly in position 3, but the 3,4-dimethyl derivative undergoes nitro-dediazoniation to the dithiole (809). Treatment of compound (808) with nitrous acid yields the phenylazo-oxadithiazapentalene (810) a similar reaction is the transformation of dioxathiapentalene (805) into the oxathiadiazapentalene (811) by the action of nitrobenzene-p-diazonium fluoroborate. ... 

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