4-chloro-l-nitro

Benzene, l-chloro-(4-methylphenylsulfo-nyl)methylthio-4-methyl-, 57, 100 Benzene, 4-chloro-l-nitro-, 55, 94 Benzene, (1-cyclohexen-l-yl)- [771-98-2], 56, 106... 

Kinetic studies on 2-, 3-, and 4-chloro-l-methylpyridinium salts showed a 30 10 ratio of the reaction rates at 50° with 4-nitro-phenoxide ion in methanol. The activation energy for reaction at the 4-position is one kilocalorie lower ( 8-fold higher rate) than for reaction at the 2-position. The reversal in rates relative to the corresponding halopyridines is the result of a much higher entropy of activation for the 2-chloro compound. The 3-chloro compound has a favorable entropy of activation also, but the energy of activation is about 13 kcal higher than that of the isomers (cf. Table II and Section III, A, 2). 

A number of 1-substituted 4-chloro-3-nitro-l,8-naphthyridin-2(lH)-ones (122) (R are the same substituents as in the scheme in Section II,A,4,a) were obtained from the corresponding 4-hydroxy-l,8-naphthyridin-2(lH)-ones (30) (91JHC2029,91MI2 92JMC4866). 

Tin(II) chloride reduction of both 4-chloro-3-nitro-l,8-naphthyridine (129, R = Cl) (79PJC1665) and 3-nitro-l,8-naphthyridine (129, R = H) (76S691) gave in 30-35% yield 3-amino-l,8-naphthyridine (130, R = H) reduction of the 4-amino-3-nitro compound (129, R = NH2) yielded 3,4-diamino-l,8-naphthyridine (130, R = NH2,37%) (79PJC1665). 

Tlie effect of substituents on chemical shifts in H NMR spectrum of 4-chloro-3-nitro-l,6-naphthyridine (78b), when compared with those of the parent 1,6-naphthyridine, show that all corresponding proton signals in 78b are shifted downfield in the range of 0.09 to 0.72 ppm. Tlie downfield of H-2 is particularly large 0.72 ppm (75MI1). 

Benzofurazan (benz-1,2,5-oxadiazole) reacted with bromine by addition to give a4,5,6,7-tetrabromo adduct. Bromine in hydrobromic acid solution 4-brominated both 5-methyl- and 5-bromo-benzofurazans (74JHC8I3). When 4,7-dinitrobenzofurazan was treated with ammonium chloride in refluxing acetic acid, nucleophilic displacement gave rise to the 4-chloro-7-nitro derivative (83URP1004375). Naphtho[l, 2-c]furazans (42) are mainly 4-halogenated, but there is minor substitution in the 8-position (73CHE1331). 

It is prepd by the action of methylamine on 4-chloro-l-nitrobenzene (Ref 5) by the action of methyl iodide (Ref 6), or methyl sulfate on 4-nit roaniline (Ref 7) or by the hydrolysis of 4-nitro-N-methylformanilide with hot coned aq HC1 (Ref 8). In a study of the effect of nitric acid concn on the prods of the nitration of N,N-dimethylaniline to form Tetryl, it was isolated in low yield by the action of nitric acid, d 1.046g/cc, plus Na nitrite on N,N-dimethylaniline (Ref 10). A eutectic mixt with N-ethyl-4-nitroaniline has been patented as a stabilizer for NC (Ref 12). Studies at NPF indicate that 4-nitro-N-methyl-aniline is superior to Centralite, 2-nitrodiphenyl-amine, or Acardite in stabilizing. NC Refs 1) Beil 12, 586, (295) 1125 ... 

Although derivatives of 2,1,3-benzoxadiazole have been used extensively to make quinoxalines (see Section 1.6.7), the corresponding selena and thia systems have been paid scant attention for that purpose. However, 5-chloro-4-nitro-2,l,3-benzoselenadiazole (456) has been used as a convenient source of 4-chloro-3-nitro-1,2-benzenediamine (457) (HCl + HI, 20°C, 2 h 88%), which was then converted into 6-chloro-5-nitro-2,3(l//,4//)-quinoxalinedione (458) (oxalic acid, 2M HCl, reflux, 2.5 h 23%). ° In addition, irradiation of 2,1,3-benzoselenadiazole (460, X = Se) or 2,1,3-benzothiadiazole (460, X = S) with dimethyl acetylenedicarboxy-late afforded, among other products, dimethyl 2,3-quinoxalinedicarboxylate (459)... 

Dauzonne has reported a simple synthesis of flavanones by radical denitration and dehalo-genation of 3-chloro-2,3-dihydro-3-nitro-2-aryl-4T/- I-benzopyran-4-ones,92 which are readily prepared by the reaction of salicylaldehydes with l-chloro-l-nitro-2-arylethenes (Eq. 7.73).93... 

Chloro-2-(2.3-dihydroxy-propyl-thio)-4-fluoro-l-nitro- E10b2,430 (F - SR)... 

Chloro-5-nitro-1-trifluoromethyl-EI0b,. 65 (F.duct) 4-Chloro-2-nitro-l-trifluoronicthyl-ElOa, 52 (Toxicity). 566 (Educt)... 

Choro-3.3.3-trifluoro-propyl)-l-nitro- EI0b2, 96 (Educt) 4-Chloro-l-(trifluorosilyl-methoxy)-ElOa, 602 (3 OR — 3 F) 4-Chloro-l-(3,3,3-trifluoro-2-lrifluo-romethyl-l-propenyl)- ElOb,442 (R CCl2 +Ar-CHO)... 

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