4-Hydroxyphenyl structures

Benzothiazole, 2-ethoxycarbonyl-6-hydroxy-synthesis, 6, 325 Benzothiazole, 2-ethyl-reactions, 6, 276 Benzothiazole, hexahydro-synthesis, 5, 120 Benzothiazole, 2-hydroxy-reactions, 6, 285 synthesis, 6, 322, 324 Benzothiazole, 2-(o-hydroxyphenyl)-structure, 6, 238 Benzothiazole, 2-lithio-... 

Sipila, J., and Syrjanen, K. (1995) Synthesis and NMR spectroscopic characterization of six dimeric arylglycerol- 3-aryl ether model compounds representative of syringyl and/7-hydroxyphenyl structures in lignins. On the Aldol reaction in b-ether preparation. Holzforschung 49(4), 325-331. 

The structures of the isoxazoles (393) were all consistent with their mass spectral fragmentation patterns. The reaction of hydroxylamine with 3-phenylchromone (394) gave exclusively 5-(o-hydroxyphenyl)isoxazole (395) (78ACH(97)69). 

Treatment of 2- p-hydroxyphenyl)ethyl bromide with basic alumina produces a white solid mp, 40-43°C IR, 1640cm Uy 282nm in H20,261 mm in ether NMR, two singlets of equal intensity at 1.69 and 6.44 ppm ftom TMS. Anah C, 79.97 H, 6.71. Suggest a reasonable structure for this product and a rationalization for its formation. 

Therapeutic Function Analgesic, antipyretic Chemical Name N-(4-hydroxyphenyl)acetamlde Common Name Paracetamol, Acetylfl-Aminophenol, APAP Structural Formula ... 

Chemical Name 4-butyl-1 -(4-hydroxyphenyl)-2-phenyl-3,5-pyrazolidinedione Common Name p-hydroxyphenylbutazone Structural Formula oh... 

Thus, the 2-methyl derivative of the imidazopyrazinone (above) dissolved in DMSO spontaneously emits blue light (A.max 450 nm) in the presence of air (Goto, 1968), like the 2-benzyl derivative (Amax 475 nm), the 2-methyl-6(p-hydroxyphenyl) derivative (MCLA 7max 468 nm), and coelenterazine (Amax 465 nm) under similar conditions (Fig. 5.3). The comparison of the luminescence spectra of these compounds shows that the 6-position substituent has little influence on the luminescence spectrum of coelenterazine derivatives, despite the apparent conjugation between the 6-phenyl ring and the imidazopyrazinone ring in the structures of MCLA and coelenterazine. 

Pedersen and coworkers10 studied the El mass spectra of several alkyl 2-hydroxyphenyl sulfoxides (10) and found that, contrary to methyl phenyl sulfoxide2,11 and the corresponding sulfones10, they do not show any abundant skeletal rearrangement ions (see Section III). This is obviously due to an ortho effect as shown in structure 10. 

Using 4,4,-bis(4-hydroxyphenyl)pentanoic acid (BHPA)196 197 as comonomer, some polysulfones with pendent carboxylic groups were successfully synthesized.198199 Table 6.1 shows the structure of BHPA. The functional groups can be used for the preparation of graft copolymers. 

The a-oxoalkanephosphonic acids may also serve as starting materials for other interesting structures. They can be reacted with phenols catalyzed by Lewis acids adding two p-hydroxyphenyl groups [145]. This reaction may be of some interest by using long-chain alkyl phenols. 

The following abbreviations are used salenH2 = bis(salicylalde-hyde)ethylenediimine, salH = salicylaldehyde, SAB = 2-hydroxy-iV-(2-hydroxybenzylidine)aniline dianion, SAT = 2-(o-hydroxy-phenyDbenzothiazoline dianion, SAP = iV-(2-hydroxyphenyl)salicyl-adldimine dianion, and HMPT = hexamethylphosphoric triamide , and structures marked with an asterisk ( ) are polymeric, usually by in-termolecular association. 

In a related series of experiments, the amino group and/or the carboxylic acid group of tyrosine were replaced by hydrogen atoms. The corresponding tyrosine derivatives are 3-(4 -hydroxyphenyl)-propionic acid, commonly known as desaminotyrosine (Dat), and tyramine (Tym) (structures 3-5). 

Bohman and Allenmark resolved a series of sulphoxide derivatives of unsaturated malonic acids of the general structure 228. The classical method of resolution via formation of diastereoisomeric salts with cinchonine and quinine has also been used by Kapovits and coworkers " to resolve sulphoxides 229, 230, 231 and 232 which are precursors of chiral sulphuranes. Miko/ajczyk and his coworkers achieved optical resolution of sulphoxide 233 by utilizing the phosphonic acid moiety for salt formation with quinine. The racemic sulphinylacetic acid 234, which has a second centre of chirality on the a-carbon atom, was resolved into pure diastereoisomers by Holmberg. Racemic 2-hydroxy- and 4-hydroxyphenyl alkyl sulphoxides were separated via the diastereoisomeric 2- or 4-(tetra-0-acetyl-D-glucopyranosyloxy)phenyl alkyl sulphoxides 235. The optically active sulphoxides were recovered from the isolated diastereoisomers 235 by deacetylation with base and cleavage of the acetal. Racemic 1,3-dithian-l-oxide 236... 

However, 4-amino-l,2-dihydro-5-(2-hydroxyphenyl)-3H-pyrazol-3-one and 5-amino-6-6-(2-hydroxyphenyl)pyrimidin-4(3H)-one appear to be interesting structures for developing new analgesic agents. 

Goff (54) synthesized an Fe(III) porphyrin with a 2-hydroxyphenyl group at one meso position (35, Fig. 12a). Under basic conditions, the system spontaneously dimerizes due to phenolate-Fe(III) coordination. The complex is very stable and was isolated and fully characterized. In the solid state, the X-ray crystal structure confirmed the structure of the assembly as a macrocyclic head-to-tail dimer with two intermolecu-... 

FIGURE 6.45 Inability of 5a-substituted derivatives to form structures analogous to o-QM 3 causes increased oxidative stability as in compounds 71 and 72. 5-(p-Hydroxyphenyl)-y-tocopherol (73) is oxidized to the conjugatively stabilized o-QM 74, the phenylogous a-tocored (75). 

Various LC-PB-MS and LC-APCI-MS comparisons have been reported on polymer additive extracts [540, 563,629,630]. The complementary character of the El and APCI modes was confirmed. Yu et al. [630] compared LC-PB-MS and RPLC-UV-APCI-MS for detection and identification of unknown additives (in the 252 to 696 Da range) in an acetonitrile extract from PP (containing Irganox 1076, Naugard XL-1 and a degradation product, NC-4, 3-(3,5-di-f-butyl-4-hydroxyphenyl) propanoic acid, 7,9-di-f-butyl-l-oxaspiro [4,5] deca-6,9-diene-2,8-dione and octadecanol-1). Comparison was based on El data (identification of chemical structure), APCI (MW information CID spectrum with limited fragmentation) and PDA (210 nm). The components were identified by El and confirmed by APCI- (with better sensitivity and linearity) MS and PDA showed... 

The stereostructure of ethyl OT-4a,7-//-7-phenyl-8-cyano-2-oxo-2,3,4,4a,7,8-hexahydropyrido[l,2-A [l,2]oxazine-8-carboxylate was confirmed by X-ray crystallography. It confirmed a trans-nng junction <20000L4007>. The structure of 2,4-diphenyl-7-o-hydroxyphenyl-5,6-dihydropyrido[2,Ttf]phthalazinium perchlorate 21 has also been established by X-ray crystallographic analysis <1995IZV296>. 

Stereostructures of a co-crystal of (li )-l- 4-[(9aA)-perhydropyrido[l,2- ]pyrazin-2-yl]phenyl -2-phenyl-7-hydroxy-l, 2,3,4-tetrahydroisoquinoline with ERa-LBD301-553/C — S triple mutant <2005JME364> and iV-[2-(4-hydroxyphenyl)ethyl]-a-propyl-3-[(4-hydroxyphenyl)methyl]-l,4-dioxo-l,2,3,4,ll,l la-hexahydro-67/-pyrazino[l,2- ]isoquinoline-3-acetamide with fructose-1,6-biphosphatase <2003JBC51176> were determined by X-ray crystallography. The structure of a complex formed from 3-[( -methylphenyl)amino]-4-[(4-methylphenyl)imino]-4//-pyrido[l,2-tf]pyrazine with sodium bis(trimethylsilyl)amide and (norbornadiene)Mo(CO)4 in THF was characterized by single crystal X-ray diffraction <1995JPR38>. 

---