Hydroxy-4.5-dimethyl-2

E7b/2, 483 6-[CH(OR)J-l,2,4-triazin + Acetyl-cyclopentan 2-Ethoxycarbonyl-4-pentyl- E7b/2, 424 [H2C = CH-C(C5H,) = CH-OR + NC-COOR] Pyridin-l-oxid 4,5-Dimethyl-2-(1-hydroxy-cyclohexyl)- E19d,... 

Cyclic siloxane-containing polymer was synthesized by the reaction of Bu2Sn(OCH3)2 with dimethyl hydroxy-terminated polysiloxane as shown in Fig. 52 [175],... 

Z)-S-Allylic ketene aminothioacetals underwent thio-Claisen rearrangement at room temperature to give iVJV-dimethyl -hydroxy a-allylic thioamides. -Hydroxy-N,N,-dimethylthioamides were deprotonated with LDA to afford a chelated dianion with Z-configuration. Alkylation of this dianion gave the corresponding Z a-hydroxy 5-allyUc... 

Xylenols also known as dimethyl phenol, hydroxy dimethyl benzene, or dimethyl hydroxy benzene have the... 

Fujimoto et al. prepared the lithium salt of p-(dimethyl hydroxy) silyl-a-phenyl-styrene and used it as initiator for the polymerization of hexamethyl cyclotrisilox-... 

Syntheses of epoxyphosphonates related to phosphonomycin (49) continue to be developed. In one synthetic scheme dimethyl hydroxy-methylphosphonate is treated with acetaldehyde in the presence of O O... 

CAS 64365-23-7 68937-54-2 68938-54-5 Synonyms Dimethylmethyl (polyethylene oxide) siloxane Dimethylsilox-ane/glycol copolymer Polyoxyethylene-grafted polydimethylsiloxane Polysiloxane polyether copolymer Siloxanes and silicones, dimethyl, hydroxy-terminated, ethoxylated propoxylated Classification Silicone glycol surfactant... 

Synonyms Dimethyl silicones and siloxanes, hydroxy-terminated Dimeth-yisiloxane, hydroxy-terminated Poly [oxy (dimethylsilylene)], a-hydro-co-hydroxy- Siloxanes and silicones, dimethyl, hydroxy-terminated Definition Dimethyl silicone terminated with hydroxyl groups Properties Anionic Toxicology TSCA listed... 

Siloxanes and silicones, dimethyl, 3-hydroxypropyl methyl, ethoxylated, propoxylated. See Dimethylsiloxane/EO-PO copolymer Siloxanes and silicones, dimethyl, hydroxy-terminat. See Dimethiconol Siloxanes and silicones, dimethyl, hydroxy-terminated, ethoxylated propoiqrlated. See Dimethicone copolyol Siloxanes and silicones, dimethyl, methyl stearyl. See Steatyl dimethicone... 

Direct insertion mass spectrometry of the metabolite Rg, 0.26 (Table 3) gave a molecular ion of 352 indicating the insertion of two atoms of oxygen into the feprazone nucleus. Also notable was a prominent ion at m/e 200 implying oxidation of the diphenyl-pyrazolidinedione nucleus, the other oxygen presumably being in the side chain. Bakke ejt al. (4) had identified a dihydroxy metabolite of phenylbutazone in the rat, therefore a dihydroxy metabolite of a diphenylpyrazolidinedione was not without precedent. With these facts in mind -methoxy-3 -hydroxyfeprazone was synthesised and it and the metabolite methylated with diazomethane. The spectra of the methylated metabolite and the methylated reference compound were almost identical (Table 3). Thus the molecular ion in both spectra corresponds to the dimethylated -hydroxy-3 - hydroxyfeprazone. 

Dimethyl (hydroxy(4-methoxyphenyl)- ( >Diethyl (1-hydroxy-3-phenylallyl)-methyl)phosphonate (3a yield 80%) phosphonate (3b yield 90%)... 

Chem. Descrip. C13-15 alkyl dimethyl hydroxy ethyl ammonium chloride CAS 85736-63-6... 

D-fMO MO-Nonitol, 2,6-anhydro-3,S,7-trideoxy-l-C-([hydroxy-(tetrahydro-2-methoxy-5,6-dimethyl-4-methylene-2 H-pyran-2-yl) acetyl] amino)-5,5-di methyl-1, S,9-tri-0-rriethyl-, 2R-[2( j(,2[S (5-q], 5P,6P] -... 

J-Pyran-2-acetamid, Ai-[[6-(2,3-dimethoxypropyl)tetrahydro-4-hydroxy-5,5-dimethyl-2H-pyran-2-yl]rriethoxymethyl]tetrahydro-a-hydroxy-2-methoxy-5,6-dimethyl-4-rTiethylene]-... 

Dimethyl Sulphate Method for hydroxy compounds and for primary and secondary amines, acid amides, etc. The substance is dissolved or suspended in water, a small excess (above the theoretical) of sodium hydroxide added and then the theoretical quantity of dimethyl sulphate, the mixture being finally shaken without external warming. Methylation is usually rapid, the dimethyl sulphate being converted to methyl hydrogen sulphate... 

A more eflicient and general synthetic procedure is the Masamune reaction of aldehydes with boron enolates of chiral a-silyloxy ketones. A double asymmetric induction generates two new chiral centres with enantioselectivities > 99%. It is again explained by a chair-like six-centre transition state. The repulsive interactions of the bulky cyclohexyl group with the vinylic hydrogen and the boron ligands dictate the approach of the enolate to the aldehyde (S. Masamune, 1981 A). The fi-hydroxy-x-methyl ketones obtained are pure threo products (threo = threose- or threonine-like Fischer formula also termed syn" = planar zig-zag chain with substituents on one side), and the reaction has successfully been applied to macrolide syntheses (S. Masamune, 1981 B). Optically pure threo (= syn") 8-hydroxy-a-methyl carboxylic acids are obtained by desilylation and periodate oxidation (S. Masamune, 1981 A). Chiral 0-((S)-trans-2,5-dimethyl-l-borolanyl) ketene thioketals giving pure erythro (= anti ) diastereomers have also been developed by S. Masamune (1986). 

Six protective groups for alcohols, which may be removed successively and selectively, have been listed by E.J. Corey (1972B). A hypothetical hexahydroxy compound with hydroxy groups 1 to 6 protected as (1) acetate, (2) 2,2,2-trichloroethyl carbonate, (3) benzyl ether, (4) dimethyl-t-butylsilyl ether, (5) 2-tetrahydropyranyl ether, and (6) methyl ether may be unmasked in that order by the reagents (1) KjCO, or NH, in CHjOH, (2) Zn in CHjOH or AcOH, (3) over Pd, (4) F", (5) wet acetic acid, and (6) BBrj. The groups may also be exposed to the same reagents in the order A 5, 2, 1, 3, 6. The (4-methoxyphenyl)methyl group (=MPM = p-methoxybenzyl, PMB) can be oxidized to a benzaldehyde derivative and thereby be removed at room temperature under neutral conditions (Y- Oikawa, 1982 R. Johansson, 1984 T. Fukuyama, 1985). 

Direct sulfonation of thiazole, as well as of 2-substituted thiazoles, leads mostly to substitution m the 5-position (330-332). 4-Thiazole sulfonic acid has been prepared through direct sulfonation of 2.5-dibromothiazole with subsequent Rane% Ni reduction (330). Sulfonation of 2.5-dimethyl- and 2-piperidyl-5-methylthiazoles affords the corresponding 4-sulfonic acids as barium salts (247). The 2-hydroxy group facilitates the sulfonation (201. 236). When the 4- and 5-positions are occupied direct sulfonation can occur in the 2-position. 5-hydroxyethyl-4-methyl-2-thiazole sulfonic acid has been prepared in this manner (7). 

Goto et al. (386) have qualitatively studied the relationship between the structure and the ease of formation of some 2-aryl- and 2-heteroaryl-A-2-thiazolin-4-one derivatives. It is found that 2-pyridyI, 2-benzimidazoyl, and 2- 6 hydroxy-5 -methyl)-benzothiazolyl derivatives are too unstable to be isolated. 6 -Hydroxy-, 6 -methyl-, and unsubstituted 2-benzothiazoiyl derivatives, as well as naphtothiazolyl derivatives are unstable but isolable. On the other hand, 6 -methoxy-. 6 -acetoxy-. and 5, 7 -dimethyl-6 -hvdroxybenzothiazolyl derivatives as well as most of their 5-methyl substituted derivatives are stable and easily prepared. 

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