4.5- Dicarboxy-2-phenyl

Imidazol 4,5-Dicarboxy-2-phenyl-E8c, 13 [HOOC — CH(OH) — CH(0H)-C00H/HN03 +... 

Benzyloxycarboiiylarmno-2-(pentafluorophcnoxycarbonyl-cthyl)-3-[2-benzyloxyciirbonyl-2-(5-benzyloxycarbonylamino-2-tert,-butyloxycarbonylamino-4-hydroxy-penlanoylamino)-ethyl]-4,4 -bis-[benzyloxy]- ElOb, 584 (Arf — OH - ArF —O —CO-R) 4,4 -Bis-[l-(3,4-dicarboxy-phenyl)-... 

Cu(II)(2-selenobenzoate)2 Cu(lI)-2,4-di(/>-carboxyphenylamino)pyrimidine Cu(II)-2,4-di(m-carboxyphenylamino)pyrimidine Cu(II)-2,4-di(o-carboxyphenylamino)pyrimidine Cu(II)2[2-(2-carboxyphenyl)amino-4-(2-carboxy-phenyl)aminopyrimidine] 2 Cu(II)2[2-carboxyphenyl)amino-4-(2,3-dicarboxy-phenyl)aminopyrimidine]... 

Poly[2,2 -bis(3,4-dicarboxy- phenyl)hexaflnoropropane- dianhydride-co-2,2 -bis(triflnoro- methyl)-4,4 -biphenyldiamine] tetrahydrofnran 2 424... 

Methylene dianiline (MDA) BASF Corporation, Wakayama Seika, Kogyo Co. 2,2-Bis (3,4-dicarboxy phenyl) hexafluoro-propane dianhydride (6FDA) Hoechst Celanese... 

CjJHuNfOj 4-Nitro-zinite6ure-anhydrld 9, 607. oSitio-y-tnixillaauie-anhydrid 17II 507. 2-Methyl-3-[2.4-dicarboxy-phenyl]-obin azolon-(4)-carbon8aiire.(6) 86 1 574. 

Bis [4-(3-Ethynylphenyl-N-phthalimide) ] hexafluoropropane (7) The bisimide was prepared from the reaction of 2,2-bis(3, 4 -dicarboxy-phenyl)hexafluoropropane dianhydride with two moles of 3-aminophenyl-acetylene in glacial acetic acid. Purification by chromatographing on silica gel provided the material with a mp 185-186 C, reported mp 180-186 C. 

The aromatic polyimide films (i 5) used in this study are listed in Table I. The dianhydride monomers 2,2-bis(3,4-dicarboxy-phenyl)hexafluoropropanedian-... 

I was made fiom 2,2 -bis(3,4 -dicarboxy-phenyl)hexafluoro-propane dianhydride (6FDA) and 2,2 -bis(3-aminophenyl)-hexafiuoropropane (3,3 -6F-diamine) n was made from 6FDA and 2,2 -biS (4-aminophenyl)hexafluoropropane (4,4 -6F-diamine)... 

Finally, it is noted that suitable enantiomers of helicenes have been applied as selector for non-helical compounds. The disodium salt of P-( +)-7,10-dicarboxy hexahelicene coated on silicagel was successfully used in resolving the N-(2,4-dinitro-phenyl)-a-amino acid esters. Good resolutions were found for alanine, isoleucine, valine, phenylalanine and phenylglycine 94). 

H-Phenoxazine 2-Amino-3-oxo-E9a, 185 (2-NH2-phenole/Oxid.) Pyridazine 3,4-Dicarboxy-5-phenyl-E9a, 642 (4-Ar — cinnoline + KMn04)... 

MeOOC COOMe (Pyrazolone) MeCN (b.p.) 2-Phenyl-l -(1, 2 -dicarboxy vinyI)-5-methyl- 499 ... 

Anhydrous piperazine refluxed with methyl formate produced I-formylpiperazine (1725), which was reduced with lithium aluminum hydride to 1-methylpiperazine (1703). l-Nitroso-4-phenylpiperazine in tetrahydrofuran with diisopropylamine, methyllithium, and carbon dioxide formed 2-carboxy-l-nitroso-4-phenylpiperazine, which was cleaved by dry hydrogen chloride in benzene to 3-carboxy-l-phenyl-piperazine (1726). Distillation of the calcium salt of rra/is-2,3-dicarboxy-l, 4-di-phenylpiperazine gave 1,4-diphenylpiperazine (1669). Reduction of 1-ethoxy-carbonyl-4-trifluoroacetylpiperazine with borane in tetrahydrofuran formed... 

Optical activity owing to restricted rotation (atropisomerism) has been demonstrated in two phenylthiophenes 2-(6-methyl-2-nitro-phenyl)-3 thiophenecarboxylic acid (41), which rapidly racemized in solution, and 2,5-dimethyl-4-(6 -methyl-2 -nitrophenyl)-3-thio-phenecarboxylic acid (42)/ which was optically stable (at room temperature). Recently the first bithienyl, 2,2 -dicarboxy-4,4 -dibromo-5,y-dimethyl-3,3 -bithienyl (43), has been resolved into optical anti-podes " which were optically stable. 

Experimental. The general conditions of experiments, and methods of investigations were similar to those described previously.However, extremely precise and reproducible results of crosslinking were achieved owing originally developed device for exposure (Pig in which the specimens may be rotated with chosen rate. Additionally, the selection of UV-sensitizers was ex-tented, and besides diphenyl sulphoxide, also dinaphtyl sulphoxide, methyl - benzyl sulphoxide, bis- p-chloro-phenyl sulphoxide, bis- 2,4-dichlorophenyl sulphoxide, were used. Also, some other compounds were examined, namely diphenyl sulphide and its p-nitro-p-amino- as well o,o-dicarboxy-derivatives, methiomethy-lene-diethyl phosphate and uranyl acetate. 

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