Dioxane, solubility

The water-insoluble lignin amounted to about one-third, and the hexane-dioxane soluble lignins (which were mostly monomers) to about 20%, of the lignins dissolved. 

Physical Data mp 135 °C [aj —24.2° (1.7, dioxane). Solubility sol Et20, THF, aq NaHCOs solution insol cold H2O. Preparative Methods hydrolysis of the corresponding anhydride obtained by headng (2) ,3) )-tartaric acid and pivaloyl chloride at 120-140 °C for 4 h. ... 

Sol in acet, tetrahydrofuran and eth acetate, si sol in n-heptane and methanol v si sol in toluene and w. Prepn of the initial polymer is from a dioxane soln at 50° of 2.0 equiv mol wts each of the monomers using either 1.5 equiv wt % of boron trifluoride etherate or 2.0 equiv wt % of vanadyl acetylacetonate as a catalyst to enhance the polymerization rate. Complete polymerization or gel is accomplished in about 70 hrs at 50°. The reaction rate is further enhanced by the addition of 0.072 equiv wt % of the isocyanate monomer after the initial reaction, resulting in gelation after 40 hrs at 50°. The hot dioxane soluble product is w pptd, vacuum steam-distd and dried. Post polymerization nitration of the polymer is accomplished with 100% nitric acid at 65°... 

Needles from alcohol + petr ether, mp 296. [n]g +86 (ale) [ctjff +145.5 (dioxane) [ajg1 +163 (chloroform). Freely sol in chloroform, dioxane. Soluble in alcohol, pyridine, acetic acid. Practically insol in petr ether. 

Lanaroside A, Ci9H76Ol9, Digilanide Ay Adigal- Long, flat prisms from methanol, dec 245-248, [ajg1 +31,6 CO,48 g in 25 ml 95% ale) [ ] +23-2° (0.95 g in 25 ml dioxane). Soluble in 20 parts methanol, 40 parts alcohol, 225 parrs chloroform, 16,000 parts water. 

Crystals from hexane, mp 161-166. Stable in air. [ ] 469 to 475 (dioxane). Soluble in alcohol, methanol, ether and in other organic solvents. Sparingly sol in vegetable oils. Practically insol in water. 

PHYSICAL PROPERTIES colorless crystals or white to off-white powder odorless or slight, aromatic odor insoluble in water practically insoluble in dilute acids and alkalies soluble in acetone, benzene, ether, carbon tetrachloride, kerosene, morpholine, tetralin, and tributyl phosphate freely soluble in pyridine and dioxane solubility in organic solvents increases with elevated temperatures MP (108.5-109°C, 227-228°F) BP (260°C, 500°F) DN (1.5 g/cm ) SG (0.99 at 20°C) VP (1.5 x 10 mmHg at 20°C) UV MAX (236nm). 

COOMe MoCl5/60°C low mol. wt. polymer, dioxane-soluble Masuda 1982d... 

Polymers produced in toluene, hexane, or chloroform, even when the concentration of monomer is 70-8097o, are essentially not syndiotactic. The polymers produced in the solid phase consist of an atactic fraction (/.e., a dioxane-soluble fraction), a syndiotactic fraction (/.e., a fraction soluble in dioxane-water mixture), and an insoluble gel. 

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