4.5- Diethyl-2-hydroxy

In recent years, possible alternatives to hydrazine have been suggested, and some have been used on plant. These include carbohydrazide (NH2NHCONHNH2), derivatives of hydroxylamine, e.g. diethyl hydroxy-lamine (HONfCiHjIi), ketoximes, and erythrobic acid (iso corbic acid). These are usually faster scavengers than hydrazine or activated hydrazine . 

Malondioate Diethyl Hydroxy-(tctrafluoro-2-trifluoromethyl-propanoyl)-FJObj, 51 [C = C —C - OH-OO-CH(OH)] C,II,2BrFO... 

Some preparations are described in Section 1C(1) and additional preparative data are as follows. Aminoacetonitrile with hydroxylamine gave 2,5-bishydroxy-iminopiperazine (92) (465), which was hydrolyzed with dilute hydrochloric acid to the monoxime in contrast, nitrous acid converted the dioxime (92) into piperazine-2,5-dione (465). fV-(Aminoacyl)aminoacetonitrile with hydroxylamine formed 5-hydroxyiminopiperazin-2-one (1619). Reduction of diethyl hydroxy-iminomalonate in ethanol with hydrogen over palladium-charcoal gave diethyl aminomalonate and 3,6-diethoxycarbonylpiperazine-2,5-dione (821) and heating of diethyl A -methylaminomalonate formed 3,6-diethoxycarbonyl-l,4-dimethyl-piperazine-2,5-dione (1620), which with sodium hydride in dioxane followed by treatment with sulfur monochloride gave 3,6-epidithio- (93) and 3,6-epitetrathio-... 

Diethyl (hydroxy(3-nitrophenyl)methyl) phosphonate [5b yellow solid, mp 92-94 C, P (OEt)3 1.3 equiv ZnBr2 1.1 equiv reaction time 4h yield 80%]... 

Benzaldehyde, finely cut Zn-foil, and abs. ether added to a dry mixture of a-bromo-a,a-diethylacetamide and benzene, iodine crystals added at 20°, and refluxed 2 hrs. a, -diethyl- -hydroxy-j6-phenylpropionamide. Y 77%. F. e. s. A. V. Sivertseva, Tr. Leningr. Khim.-Farmatsevt. Inst. 1962(14), 7 G. A. 60, 15769h. 

Diethyl (furan-2-yl(hydroxy)methyl)- Diethyl (hydroxy(thiophen-2-yl)methyl)- Diethyl (1-hydroxyhexyl)phosphonate phosphonate (4a time 3 h yield 99 ) phosphonate (4b time 18 h yield 96%) (4c time 15 h yield 99%)... 

Diethyl (hydroxy(3-nitrophenyl)methyl) phosphonate (17a, yellow solid yield 80%)... 

The first practical method for asymmetric epoxidation of primary and secondary allylic alcohols was developed by K.B. Sharpless in 1980 (T. Katsuki, 1980 K.B. Sharpless, 1983 A, B, 1986 see also D. Hoppe, 1982). Tartaric esters, e.g., DET and DIPT" ( = diethyl and diisopropyl ( + )- or (— )-tartrates), are applied as chiral auxiliaries, titanium tetrakis(2-pro-panolate) as a catalyst and tert-butyl hydroperoxide (= TBHP, Bu OOH) as the oxidant. If the reaction mixture is kept absolutely dry, catalytic amounts of the dialkyl tartrate-titanium(IV) complex are suflicient, which largely facilitates work-up procedures (Y. Gao, 1987). Depending on the tartrate enantiomer used, either one of the 2,3-epoxy alcohols may be obtained with high enantioselectivity. The titanium probably binds to the diol grouping of one tartrate molecule and to the hydroxy groups of the bulky hydroperoxide and of the allylic alcohol... 

A[,A/-diethyl-l,3,4,6,7,ll -hexaliydro-2-hydroxy-9,10-dimethoxy-2Ff-ben2o-(i7)-quinoli2ine-3-carboxamide acetate hydrochloride) (16) may be made by the method described in Reference 14. 

Amino-4-nitrophenol. This derivative, 2-hydroxy-5-nitroani1ine (9), forms orange prisms from water. These prisms are hydrated with one water of crystallization, mp 80—90°C, and can be dehydrated over sulfuric acid to the anhydrous form, mp 143 —145°C. The compound is soluble in ethanol, diethyl ether, acetic acid, and warm benzene and slightly soluble in water. 

A A Dimethylamino)phenol. 3-Hydroxy-A7,A7-dimethylariiline (14) forms white needles and is soluble in alkaU, mineral acid, ethanol, diethyl ether, acetone, and benzene and practically insoluble in water. 

A Methylamino)phenol. This derivative, also named 4-hydroxy-/V-methy1ani1ine (19), forms needles from benzene which are slightly soluble in ethanol andinsoluble in diethyl ether. Industrial synthesis involves decarboxylation of A/-(4-hydroxyphenyl)glycine [122-87-2] at elevated temperature in such solvents as chlorobenzene—cyclohexanone (184,185). It also can be prepared by the methylation of 4-aminophenol, or from methylamiae [74-89-5] by heating with 4-chlorophenol [106-48-9] and copper sulfate at 135°C in aqueous solution, or with hydroquinone [123-31 -9] 2l. 200—250°C in alcohoHc solution (186). 

A A Dimethylamino)phenol. 4-Hydroxy-Ai,A/-dimethylaniline (20) forms large rhombic crystals from diethyl ether—hexane or diethyl ether—ligroin. It forms a salt with sulfuric acid, mp 208—210°C (187). 

Fusion/Hydroxylation. The conversion of arylsulfonic acids to the corresponding hydroxy compound is normally effected by heating with caustic soda (caustic fusion). The primary examples are P-naphthol in the naphthalene series and resorcinol in the benzene series further examples are m- am in oph en o1 from metanilic acid and diethyl-y -arninophenol from /V,/V-diethy1metani1ic acid. In the naphthalene series the hydroxy group is much... 

The O-alkyl derivatives of those A-oxides, which exist partly or entirely as (V-hydroxy tautomers, may be made by primary synthesis (as above) or by alkylation. Thus, 5,5-diethyl-1-hydroxybarbituric acid (936 R = H) with methyl iodide/sodium ethoxide gives the 1-methoxy derivative (936 R = Me) or with benzenesulfonyl chloride/ethoxide it gives the alkylated derivative (936 R = PhS02) (78AJC2517). 

Diethyl 4-hydroxyisoxazole-3,5-dicarboxylate (334) was prepared by the reaction of acetonedicarboxylic acid ester with nitrosyl chloride (78JHC1519). Other 4-hydroxyisoxazoles have been prepared by the reaction of 2-hydroxy (or acetoxy)-1,3-diketones with hydroxylamine (34JA2190, 62HC(i7)i, p. 149), and by hydrolysis of 4-isoxazolediazonium salts (62HC(17)1, p. 149). The parent 4-hydroxyisoxazole has not yet been reported. 

The first in this series to be reported was 4-oxoisoxazoline-3,5-dicarboxylic acid diethyl ester, which was formed by the reaction of nitrous acid on diethyl acetonedicarboxylate in 1891. Quilico described a number of syntheses in his 1962 review and the most general include the reaction of hydroxylamine and a-hydroxy-(or acetoxy)- 3-diketones and the conversion of 4-isoxazolediazonium salts to the hydroxy moiety (62HC(17)1, p. 3). Additional syntheses reported were the oxygenation of a 4-boric acid derivative (67JOM(9)l9) and peroxide oxidation of a 4-nitro-2-isoxazoline (Scheme 151) (79ZOR2436). 

Phenylacetonitrile reacts with diethyl sulfite to give 3-hydroxy-4,5-diphenylisothia2ole, together with other products (75SST(3)541). Phenylketene reacts with compound (199) to give a mixture of the isothiazolidinone (200) and the pyrrole (201 Scheme 33) (77SST(4)339, 79SST(5)345). 

Benzo[b]furan-2-carboxylic acid, 6,6 -[(2-hydroxy-l,3-propanediyl)bis(oxy)]bis(3-hydroxy-diethyl ester trisodium salt trihydrate applications, 4, 709... 

Furoxans, diethyl-synthesis, 6, 423 Furoxans, dihalo-synthesis, 6, 423 Furoxans, dimethyl-NMR, 6, 397 O NMR, 6, 398 Furoxans, diphenylring cleavage, 6, 404 synthesis, 6, 423 Furoxans, hydroxy-reactions, 6, 414 Furoxans, mercapto-reaotions, 6, 414 Furoxans, nitro-as explosives, 6, 426 reactions, 6, 413-414 reduction, 6, 423 Furoxans, phenyl-reactions... 

Isoxazole-3,5-dicarboxyIic acid, 4-hydroxy-diethyl ester synthesis, 6, 85, 87 synthesis, 6, 66... 

Pyrazolidine, l,2-diethyl-3-hydroxymethyl-biological activity, 5, 297 Pyrazolidine, 2-ethoxycarbonyl-l-phenyl-reactions, 5, 257 Pyrazolidine, 4-hydroxy-synthesis, 5, 155 Pyrazolidine, 1-phenyl-... 

Pyrrole-3,5-dicarboxylic acid, 1-aryl-2-hydroxy-diethyl ester synthesis, 4, 123... 

The purification of diethyl ether (see Chapter 4) is typical of liquid ethers. The most common contaminants are the alcohols or hydroxy compounds from which the ethers are prepared, their oxidation products (e.g. aldehydes), peroxides and water. Peroxides, aldehydes and alcohols can be removed by shaking with alkaline potassium permanganate solution for several hours, followed by washing with water, concentrated sulfuric acid [CARE], then water. After drying with calcium chloride, the ether is distilled. It is then dried with sodium or with lithium aluminium hydride, redistilled and given a final fractional distillation. The drying process should be repeated if necessary. 

Hydroxy-3-methylgIutaric acid (Meglutol) [503-49-1J M 162.1, m 99-102 , 108-109 , 100 , pKestd) 4.0, pK star -O. Recrystd from diethyl ether/hexane and dried under vac at 60° for Ih. 

Hydroxy-2-methylpropionic acid (a-hydroxyisobutyric acid, 2-methyllactic acid)) [594-6I-6J M 104.1, m 79 , b 114 /12mm, 212 /760mm, pK 3.78. Distd in steam, crystd from diethyl ether or benzene, sublimed at 50° and dried under vacuum. 

Patulin 4-hydroxy-4ff-furo[3.2-c]pyran-2(6ff)-one [149-29-1] M 154.1, m 110 . Crystd from diethyl ether or chloroform. (Highly TOXIC). 

Phthiocol (2-hydroxy-3-methylnaphthaquinone) [483-55-6] M 188.1, m 173-174°, pK, -4.2. Crystd from diethyl ether/pet ether. 

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