Xylylene dichloride

A. p-Xylylene-bis(lriphenylphosphonium chloride). A mixture of 262 g. (1.0 mole) of triphenylphosphine (Note 1) and 84 g. (0.48 mole) of J)-xylylene dichloride (Note 2) in 1 1. of dimethyl-formamide is heated at reflux with stirring for 3 hours (Note 3). The mixture is then allowed to cool to room temperature with stirring, and the white crystalline solid is collected, washed with 100 ml. of dimethylformamidc followed by 300 ml. of ether, and... 

The higher solubility of several quaternary ammonium salts of glyphosate in polar aprotic organic solvents such as acetonitrile was discovered (2), which permitted their reaction in solution with various alkyl halides. For example, GLY(n-Bu4N)2H reacted with either o-xylylene dichloride or 1,5-dibromopentane to produce the interesting quaternary glyphosate derivatives 81 and 82, whose structures have been confirmed by x-ray analysis (2). 

A PPV derivative which is twofold phenylsubstituted at the vinylene unit, poly(l,4-phenylene-l,2-diphenylvinylene DP-PPV), (71b) (see also the discussion of dehydrochlorination of unsymmetrically substituted para-xylylene dichlorides in Section 3.1) was first synthesized by Smets et al., using acid-catalyzed elimination of nitrogen from l,4-bis(diazobenzyl)benzene 83 [106]. The yellow products obtained are fully soluble in common organic solvents (toluene, chloroform, ethylene chloride, DMF, THF). 

Methoxy-5-(2-ethylhexyloxy)-p-xylylene dichloride and triethyl phosphate were initially reacted to generate the corresponding phosphonate. Thereafter a mixture of the phosphonate (0.016 g), the Sep 1 product (0.5 g), and 50 ml of THF was charged into a reactor and treated dropwise at ambient temperature with potassium t-butoxide (0.07 g) dissolved in 5 ml of THF over a 10 minute period. The mixture reacted for 2.5 hours at ambient temperature and was then neutralized with acetic acid. The polymer was precipitated by pouring into methanol and dried, and the product was isolated. 

Tetrakis(hydroxymethyl)-m-terphenyl 9 [10] and its deutero analog 9-D have also been successfully employed as templates for oxacuppedophanes. Treatment of tetraalcohol 9 with 1,3-xylylene dichloride (142) in DMF in the presence of NaH gave a 42% yield of tetraoxacuppedophane 149 [10] [Eq. (15)]. The appearance of the H2- resonance at 56.71 (verified by the synthesis of 149-D)... 

Figure 7.1 Equilibrium swelling in toluene vs concentration of initial polystyrene solution for the networks crosslinked with (1, 2) p-xylylene dichloride and (3) monochlorodimethyl ether to crosslinking degrees (1) 11, (2) 100, and (3) 43%.

Figure 7.5 Dependence of volume swelling in (1) n-hexane (2) methanol and (3) water on the crosslinking degree of networks prepared by crosslinking linear polystyrene with (a) p-xylylene dichloride and (b) methylal.

Table 7.2 Swelling (mlVg) of polymers based on linear polystyrene crosslinked with p-xylylene dichloride (measured by the weight of the dry and swollen product) Solvent Degree of crosslinking, (%)...

Table 7.7 Apparent density (papp g/cm ) and total pore volume (Mfo/CmVg) of hypercrosslinked networks based on linear polystyrene with a molecular weight of 3 X 10 Da and crosslinked with p,p-bis-chloromethyl-diphenyl, p-xylylene dichloride, or monochlorodimethyl ether...

XDC =p-xylylene dichloride DMM = dimethoxymethane CMM = tris(chloromethyl)mesitylene ... 

Hypercrosslinked networks were prepared by crosslinking linear polystyrene (I) with p-xylylene dichloride and styrene—0.7% DVB copolymer (II) with monochlorodimethyl ether X= 100%. 

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