Structure aryl-diones

Fig. 7-30. Examples of proposed leucochromophoric and chromophoric structures. Aryl-coumarones (1) and stilbene quinones (2) are thought to be formed from stilbenes after oxidation. Butadiene quinones (3) could arise from oxidation of hydroxyarylbutadienes being formed from phenolic pinoresinol structures during kraft or neutral sulfite pulping. Cyclization may yield intermediates which are further oxidized to cyclic diones (4). A resonance-stabilized structure (5) results from the corresponding condensation product formed during pulping. o-Quinoid structures (7) are oxidation products of catechols (6) formed during alkaline or neutral pulping processes.

Hydantoin — see also Imidazolidine-2,4-dione Hydantoin, 3-aryl-5-benzyl-structure, 5, 351... 

H,3H- Pyrrolo[l, 2-c]oxazole-l, 3-dione, 5,6,7,8-tetrahydro-IR spectra, 6, 978 [2.2](2,5)Pyrrolophane, N-aryl-rearrangements, 4, 209 Pyrrolophanes natural products, 7, 764 synthesis, 7, 771 Pyrrolophanes, N-aryl-synthesis, 7, 774 (2,4)Pyrrolophanes synthesis, 7, 771 Pyrrolo[3,4-c]pyran-4-ones synthesis, 4, 288 Pyrrolopyrans synthesis, 4, 525, 526 Pyrrolopyrazines synthesis, 4, 526 Pyrrolo[l, 2-a]pyrazines synthesis, 4, 516 Pyrrolo[2,3-6]pyrazines Mannich reaction, 4, 504 Vilsmeier reaction, 4, 505 Pyrrolo[3,4-c]pyrazole, 1,3a,6,6a-tetrahydro-structure, 6, 976 synthesis, 6, 1019 Pyrrolopyrazoles synthesis, 5, 164 Pyrrolo[l,2-6]pyrazoles synthesis, 6, 1002, 1006 Pyrrolo[3,4-c]pyrazoles reactions, 6, 1034 synthesis, 6, 989, 1043 Pyrrolo[3,4-c]pyrazolones synthesis, 6, 989 Pyrfolopyridazines synthesis, 4, 517 Pyrrolo[l, 2-6]pyridazines synthesis, 4, 297 6/7-Pyrrolo[2,3-d]pyridazines synthesis, 4, 291 2/f-Pyrrolo[3,4-d]pyridazines synthesis, 4, 291 6/7-Pyrrolo[3,4-d]pyridazines synthesis, 4, 291... 

Semiempirical PM 3 MO calculations were performed on eight 4-aryl-2,3,5,6,7,8-hexahydro-l//-pyrido[l,2-c]pyrimidin-l,3-diones and on their dimers (00JPO213). In all of the calculated structures the aromatic ring is almost perpendicular to the plane of the pyrido[l,2-c]pyrimidin-l,3-dione fragment, which is in accordance with the X-ray data for 4-(4-methylphenyl) derivative. 

Characteristic H NMR data of (4a/ ,55)- and (4n5,5R)-2-substituted 5- [A-(/e/ /-butoxycarbonyl)-L-tryptophyl]amino perhydropyrido[l,2-c]pyri-midine-l,3-diones were tabulated (01JMC2219). C CPMASS NMR data of 4-(4-methoxyphenyl)perhydropyrido[l,2-c]pyrimidine were reported (00JST73). C NMR data were reported for eight 4-aryl-2,3,5,6,7,8-hexahydro-l//-pyrido[l,2-c]pyrimidin-l,3-diones in the solid state and in CDCI3 solution (00JPO213). The structure of 4-aryl-3,4-dihydro-2//-pyrido [l,2-c]pyrimidine-l,3-diones and their 2,3,5,6,7,8-hexahydro derivatives were characterized by H and C NMR data (99JHC389). Conformational analysis of 6-methyl-2,3,4,6,7,ll/)-hexahydro-l//-pyrimido[6,l-n]isoquino-lin-2-ones 138 and 139 were carried out by H and C NMR studies (97LA1165). 

The first reported chiral catalysts allowing the enantioselective addition of diethylzinc to aryl aldehydes in up to 60% cc were the palladium and cobalt complexes of 1,7,7-trimethylbicy-clo[2.2.1. ]heptane-2,3-dione dioxime (A,B)3. A number of other, even more effective catalysts, based on the camphor structure (C K, Table 26) have been developed. 

In the early 1970 s potent acaricidal activity in 3-aryl-4-hy-droxy-coumarins. III, and 2-aryl-l,3-indanediones, IV, and their enol esters was discovered at Union Carbide (1,2). Extensive synthesis and screening of analogs in the dione and enol ester series led to the field test candidates Va and Vb, active against both motile forms (mite) and eggs. Va and Vb embodied certain structural and physicochemical features shown by published QSAR studies (2,3) to be important in determining the level of activity in the 1,3-indanedione series (1) the dimension D2 across the aryl ring must be near 7A and symmetry is preferred (2) the... 

Overview of the Databank. A profile of the Phase I databank of compounds is presented in Tables II-IV 202 of the 2652 permutations possible from 12 dione moieties, 13 aryl substitution patterns, and 17 different enol ester acyl groups constituted the Phase I dataset. The structures and data given below exemplify how activity varied with structure throughout the dataset. 

The structures of 4-aryl-2,3-dihydro-lH-pyrido[l,2-c]pyrimidine-l,3-diones hydrochlorides 50 were characterized by solid-state 13C CPMAS NMR spectroscopy (08JST325). 

Figure 2. l-Substituted-5-Aryl-l,5-Benzodiazepine-2,4-diones General Structure. 

Cyclocondensation of 3-amino-5-methylpyrazole with 2-arylmethyli-dene-5,5-dimethylcyclohexane-l,3-diones or 9-aryl-3,3,6,6-tetramethyl-2,3,4,5,6,7,8,9-octahydro-lH-xanthene-l,8-diones, in DMF or methanol gave 4-aryl-3,7,7-trimethyl-l,4,6,7,8,9-hexahydropyrazolo[3,4- 7]quinolin-5-ones 323 whose structure was proved by the X-ray diffraction data (06RJOC1015). 

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