125:167560
Preparation of 4-alkoxyphenols from 1,4-dihydroxybenzene.
Saito, Toranosuke; Hirayama, Takumi; Sakaguchi, Shigeo (Sanko Kaihatsu Kagaku Kenk, Japan). Jpn. Kokai Tokkyo Koho JP 08151343 A2 11 Jun 1996 Heisei, 5 pp. (Japan). CODEN: JKXXAF. CLASS: ICM: C07C043-23. ICS: B01J027-06; B01J031-02; C07C041-09. ICA: C07B061-00. APPLICATION: JP 94-294775 29 Nov 1994. DOCUMENT TYPE: Patent CA Section: 25 (Benzene, Its Derivatives, and Condensed Benzenoid Compounds) Section cross-reference(s): 35
4-HOC6H4OR (I; R = lower alkyl), useful as polymn. inhibitors for vinyl monomers, stabilizers for polyesters, and intermediates for drugs, agrochems, and, dyes are prepd. by addn. of H2O2 to a mixt. of 1,4-C6H4(OH)2 (II), ROH, and ³1 of I, HI, metal iodides, and alkali metal iodates followed by addn. of acid catalysts or by addn. of H2O2 to a mixt. of II, ROH, ³1 of HI, metal iodides, and alkali metal iodates, and acid catalysts. An aq. H2O2 soln. was added dropwise to a mixt. of II, MeOH, H2SO4, and I at 60° over 3 h and the reaction mixt. was further stirred at 60-70° for 6 h to give a product contg. 87.3% I (R = Me), vs. 54% for a control using no I.
125:86240
Methods for the preparation of hydroquinone monomethyl ether.
Teng, Dianhua; Li, Tongzhen; Ma, Shuqin (Inst. Petrochem., Heilongjiang Acad. Scis., Harbin 150040, Peop. Rep. China). Huaxue Yu Nianhe, (2), 105-106 (Chinese) 1996. CODEN: HYZHEN. ISSN: 1001-0017. DOCUMENT TYPE: Journal; General Review CA Section: 25 (Benzene, Its Derivatives, and Condensed Benzenoid Compounds)
A review with 9 refs. on different methods for prepn. of hydroquinone monomethyl ether with the emphasis on the methods using hydroquinone and methanol as raw materials, an acid as catalyst, and benzoquinone as co-catalyst
124:260570
Process for the preparation of hydroquinone monoalkyl ethers.
Caproiu, Miron Teodor; Banciu, Anca Adriana; Olteanu, Emilia (Combinatul Petrochimic, Pitesti, Rom.). Rom. RO 105090 B1 1 Nov 1994, 5 pp. (Romania). CODEN: RUXXA3. CLASS: ICM: C07C043-115. APPLICATION: RO 89-143326 18 Dec 1989. DOCUMENT TYPE: Patent CA Section: 25 (Benzene, Its Derivatives, and Condensed Benzenoid Compounds)
The title ethers were prepd. by treating hydroquinone with an alc. in presence of an oxidizing agent and a dehydrating agent in the alc. as solvent, or using another solvent. Thus, hydroquinone was treated with MeOH, H2O2, and H2SO4 under reflux for 6 h to give 70.5% 4-HOC6H4OMe of 98.7% purity.
121:270800
Effect of substituted groups on the retention of monosubstituted phenols in reversed-phase liquid chromatography.
Kim, Hoon-Joo; Lee, In-Ho; Lee, Dai Woon (Anal. Sci., R and D Cent., Daejeon 305-343, S. Korea). J. Korean Chem. Soc., 38(
, 562-9 (Korean) 1994. CODEN: JKCSEZ. ISSN: 1017-2548. DOCUMENT TYPE: Journal CA Section: 80 (Organic Analytical Chemistry) Section cross-reference(s): 22
The retention data of twenty one monosubstituted phenols in the eluent systems contg. 30-70% of methanol or acetonitrile as org. modifiers, on C18 and Ph columns were collected to study the effect of the substituted groups on the retention of phenols. The capacity factors of the solutes except amino phenols are greater on C18 than on Ph column. And all the solutes showed greater capacity factors in methanol-water than that in acetonitrile-water as a mobile phase. Generally the elution order between meta and para isomers of monosubstituted phenols in consistent (p < m) regardless of the polarity of the substituted group. But the elution order between ortho and meta isomers of phenol varies with regard to the polarity of the substituted group. The retention of the monosubstituted phenols was influenced by the interaction between the solute and unreacted silanol of columns as well as the interaction between the solute and C18 or Ph group of columns. The effect of unreacted silanol on the retention of the monosubstituted phenols is greater on C18 than on Ph column. The greater hydrogen bonding acceptor basicity(b) of the substituted group is, the greater this effect is. The relation between the retention of the monosubstituted phenols and their parameters such as van der Waals vol. (VWV) and hydrogen bonding acceptor basicity(b) was studied. The good linearity was obsd. in the plot log k' vs. (1.1VWV/100-1.84b). In consequence, the retention of the monosubstituted phenols on C18 and Ph columns can be easily predicted by the parameter (1.01VWV/100-1.84b)
118:124199
Etherification of phenols with lower alcohols.
Uohama, Misao; Takahashi, Katsuji (Dainippon Ink and Chemicals, Inc., Japan). Jpn. Kokai Tokkyo Koho JP 04305546 A2 28 Oct 1992 Heisei, 6 pp. (Japan). CODEN: JKXXAF. CLASS: ICM: C07C043-205. ICS: B01J023-24; B01J027-02; B01J027-188; B01J031-02; C07C041-01; C07C043-23. ICA: C07B061-00. APPLICATION: JP 91-67436 30 Mar 1991. DOCUMENT TYPE: Patent CA Section: 25 (Benzene, Its Derivatives, and Condensed Benzenoid Compounds)
Phenols are etherified with lower alcs. in liq. phases in the presence of acid catalysts with removing alkyl ethers together with unreacted alcs. and H2O by distn. Catechol and concd. H2SO4 were heated at 150° with adding MeOH-catechol mixt. for 6 h to give 88.4% guaiacol
127:95082
Preparation of 4-methoxyphenol from hydroquinone and methanol at controlled pressure and temperature.
Kawasaki, Hiroshi (Idemitsu Petrochemical Co., Ltd., Japan). Jpn. Kokai Tokkyo Koho JP 09151151 A2 10 Jun 1997 Heisei, 15 PP. (Japan). CODEN: JKXXAF. CLASS: ICM: C07C043-23. ICS: B01J021-06; B01J021-12; B01J021-14; B01J029-06; C07C041-09; C07B061-00. APPLICATION: JP 95-313924 1 Dec 1995. DOCUMENT TYPE: Patent CA Section: 25 (Benzene, Its Derivatives, and Condensed Benzenoid Compounds)
4-MeOC6H4OH (I), useful as a polymn. inhibitor for acrylic compds., a stabilizer for photosensitive materials, etc. (no data), and as a synthetic intermediate, is prepd. in high conversion and selectivity by continuously feeding hydroquinone (II) and MeOH at a liq. phase to a solid acid catalyst layer at 0.5-10.0 MPa and 200-350°. The reaction is preferably performed at WHSV 0.5-30 h-1 and a MeOH/II mol ratio 3-30. A MeOH soln. of II was passed through a column packed with a-Al2O3 and N 631 (SiO2-Al2O3) at 248-254°, 4.1 MPa, and WHSV 0.85 for 7 .5 h to give a product contg. 62.7 wt.% I at II conversion 88.4%.
127:81239
Process and etherification catalysts for the production of alkyl ethers of phenols from phenols and alkanols.
Ariyoshi, Kimio; Satoh, Yuuichi; Saito, Noboru (Nippon Shokubai Co., Ltd., Japan). Eur. Pat. Appl. EP 781751 A1 2 Jul 1997, 16 pp. DESIGNATED STATES: R: DE, FR, GB, IT. (European Patent Organization). CODEN: EPXXDW. CLASS: ICM: C07C041-09. ICS: C07C043-20. APPLICATION: EP 96-309513 27 Dec 1996. PRIORITY: JP 95-342277 28 Dec 1995. DOCUMENT TYPE: Patent CA Section: 25 (Benzene, Its Derivatives, and Condensed Benzenoid Compounds) Section cross-reference(s): 45, 67
Alkyl ethers of phenols (e.g., anisole) are prepd. in high yield and selectivity by the etherification of a phenol (e.g., PhOH) with an alkanol (e.g., MeOH) in the presence of an oxide catalyst comprising a supported alkali metal (e.g., Cs) as a constituent element.
130:324980
Convenient method for the ortho-formylation of phenols.
Hofslokken, Nini U.; Skattebol, Lars (Department of Chemistry, University of Oslo, Oslo N-0315, Norway). Acta Chem. Scand., 53(4), 258-262 (English) 1999 Munksgaard International Publishers Ltd. CODEN: ACHSE7. ISSN: 0904-213X. DOCUMENT TYPE: Journal CA Section: 25 (Benzene, Its Derivatives, and Condensed Benzenoid Compounds)
Phenolic derivs. are formylated selectively ortho to the hydroxy group by paraformaldehyde with magnesium dichloride-triethylamine as base. With alkyl-substituted phenols, e.g., 2-, 3-, 4-MeC6H4OH, excellent yields of the corresponding salicylaldehyde derivs. were obtained. Similar results were obtained with 2-, 3-, and 4-chloro-substituted phenols and with 3-and 4-methoxyphenol, while 2-methoxyphenol was unreactive. A good yield of Me 3-formyl-4-hydroxybenzoate was obtained by this method as well, but generally phenols with electron-attracting groups reacted sluggishly; the long reaction times required caused the formation of byproducts, particularly MOM-derivs. of the phenols.