2- Methyl-9,10-anthraquinone

The product is filtered and dried to constant weight. The filtrate will be clear and will give no precipitate with hydrochloric acid if the conditions of condensation have been correct. 

The /8-methyl anthraquinone is pale tan in color and weighs from 118 to 130 g. (86-95 l)er cent °f the theoretical amount, based upon the weight of acid taken). It is practically pure, melting at 1730. Upon crystallization from alcohol in ihe presence of bone-black, it forms long, silken, almost colorless needles, melting constantly at 173.5° (176° cor.). 

Some investigators have used concentrated instead of fuming sulfuric acid for the condensation, but the yield is usually low and the product is always colored bright yellow by some impurity which cannot be removed by crystallization. 

The time allowed for condensation may be shortened to one-half, without affecting the yield, by maintaining the temperature at 125-130° for this length of time. 

The following unimportant preparative methods may be mentioned the production of /3-methyl anthraquinone by the reduction of 2-bromo-3-methyl anthraquinone 7 the oxidation of /3-methyl anthracene-7-carboxylic acid 8 and the reduction of 2-methyl anthraquinonyl-i-diazonium sulfate.9 

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Methyl n-amyl carbinol, 7, 62 Methyl -Amyl Ketone, 7, do, 62 /3-Methyl Anthraquinone, 4, 43... 

Pyranthrone is commonly prepared by Ullmann reaction of 1 -chloro-2-methyl-anthraquinone (100), followed by double ring closure. 

Morinda citrifolia L. M. officinalis L. Je Shu Ba Ji Tian (root) Dihydroxy methyl anthraquinone, glucoside morindin, rubichloric acid, alizarin, alpha-methyl ether, rubiadin-I-methyl ether, tannins, morindadiol, masperuloside, soranjudiol, nordamnacanthal.50-424 Treat beri-beri, cancer, lumbago, cholecystitis, increase leukocyte count, stimulate endocrine system. 

More extensive studies using somewhat higher wavelengths have been reported by Geacintov et al. (111, 112). These authors used phototendering dyestuffs notably the sodium salt of anthracene 2,7 disulfonic acid as the sensitizer in aqueous solution. For grafting to cellulose acetate and ethyl cellulose 2-methyl anthraquinone which is soluble in organic solvents was used. The mechanism proposed was the removal of a... 

Methyl anthraquinone has been obtained by the oxidation of /3-methyl anthracene by several investigators 1 and material of the same origin, obtained by the benzene-extraction of crude commercial anthraquinone,2 has been fully described. As regards the synthesis from phthalic anhydride and toluene, both the preparation and properties of />-toluyl-o-benzoic acid 3 and the complete synthesis 4 have been the subject of several papers. This acid has also been prepared from o-carbomethoxy benzoyl chloride and toluene.5 The phthalic anhydride synthesis of anthraquinone derivatives in general has received considerable attention. An account of this work, together with extensive references, is given by Barnett.6... 

A-Dihydroxy-6-methyl-anthraquinone (XIII) Physcion (XV) Anthragallol (XVIII) Anthragallol-3-fflethyl ether (XX)... 

Issaq and McNitt [585] published a computer program for peak recognition on the basis of peak areas. They investigated the reproducibility of the area of some well-separated peaks for three solutes (anthraquinone, methyl anthraquinone and ethyl anthraquinone) in the 10 solvents used for their optimization procedure. The solvents included binary, ternary and quaternary mixtures of water with methanol, acetonitrile and THF. The areas were found to be reproducible within about 2 percent. The wavelength used for the UV detector in this study was not reported. 

FIGURE 7-21. Example of use of gradient to solve the general resolution problem. (1) jS-Quinone. (2) 1,4-Naphthaquinone. (3) Anthraquinone. (4) 2-Methyl anthraquinone. (5) 2-Ethyl anthraquinone. (6) 2-Tert-butylanthraquinone. (a) Isocratic separation. Column Bondapak Cig/Corasil, 2.3 mm ID x 122 cm. Mobile phase methanol/water (50/50 v/v). Pressure 1200 psig. (b) First gradient attempt. Column same as in a. Mobile phase 0-100% methanol in water, (c) Successful gradient separation. Column same as in a. Mobile phase 30-70% methanol in water. 

The effect of temperature, and of temperature and pH on the retention of a selected group of compounds using a beta-cyclodextrin column was studied. The results indicated that a plot of Ink vs. 1/T gave linear relationships for anthraquinone, methyl anthraquinone, ethyl anthraquinone, naphthalene and biphenyl using a mobile phase of methanol/water. However, a non linear relationship was observed for a selected group of dipeptides employing a mobile phase of methanol/ammonium acetate at the following pH s 1, 5.5 and 7. The retention times decreased with an increase in the temperature of the column except that for certain dipeptides the retention times increased. The separation factor (a) values decreased by approximately 10 with increase in column temperature from 25°C to 77°C. 

EFFECT OF METHANOL IN THE ELUENT ON RETENTION. The effect of increasing the volume of the organic modifier, methanol, in the mobile phase on the retention of methyl anthraquinone and naphthalene is given in Figure i(. Methyl anthraquinone and napthalene are more soluble in methanol than in water so increasing the volume of methanol in the mobile phase should result in the increase in the solubility of both compounds, and as a result, a decrease in the retention time. Also, the presence of methanol in the mobile phase affects retention when cyclodextrin bonded columns are used. Methanol is much more tightly bound in the cyclodextrin cavity than... 

Figure Effect of volume of methanol in the eluent on the retention times of methyl anthraquinone (-0-) and naphthalene (-0-) using a B-cyclodextrin column, 4,6 x 100 mm, and a flow rate of 1 ml/min.

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