Resins solid preparations

Resins Solid preparations consisting chiefly of the resinous principles from vegetable bodies. The officially prepared resins differ from alcoholic extracts in that the latter contain all of the alcohol-soluble principles in the drugs, whereas the resins contain only the alcohol-soluble principles that are insoluble in water. The term probably arose from the Greek rheos, to flow, referring perhaps to the flow of pine resin commonly observed. ... 

The investigation of minor groove-binding polyamides was greatly accelerated by the implementation of solid-phase synthesis [48]. Originally demonstrated on Boc-y9-Ala-PAM resin with Boc-protected monomers, it was also shown that Fmoc chemistry could be employed with suitably protected monomers and Fmoc-y9-Ala-Wang resin (Fig. 3.8) [49]. Recently, Pessi and coworkers used a sulfonamide-based safety-catch resin to prepare derivatives of hairpin polyamides [50]. Upon activation of the linker, resin-bound polyamides were readily cleaved with stoichiometric quantities of nucleophile to provide thioesters or peptide conjugates. 

Tripeptides with N-terminal anthranilic acid part were used as starting materials in the solid-phase synthesis carried out on TentaGel resin to prepare 1,4,11,1 l -tetrahydro-2//-pyrazino[2,l-3]quinazoline-3,6-diones with various N-l and N-3 substituents <2003EPP1471066>. Tandem cyclization from [6+0] atom fragments took place in the solid-phase synthesis of 143 from 142. Intermediate 141 was built on bromoacetal resin (Scheme 17) <1998JOC3162>. 

The cyclization of IV-allyl-o-haloanilines was adapted to the solid phase for both indoles [332, 333] and oxindoles [334]. For example, as illustrated below, a library of l-acyl-3-aIkyl-6-hydroxyindoles is readily assembled from acid chlorides, allylic bromides, and 4-bromo-3-nitroanisole [332], Zhang and Maryanoff used the Rink amide resin to prepare Af-benzylindole-3-acetamides and related indoles via Heck cyclization [333], and Balasubramanian employed this technology to the synthesis of oxindoles via the palladium cyclization of o-iodo-N-acryloylanilines [334], This latter cyclization route to oxindoles is presented later in this section. 

Preparation of 2a-2g. The diacid chloride precursor was prepared by substituting adipoyl chloride for terepthaloyl chloride in Bilibin s procedure (17). Reaction of this precursor with diols was carried out as described for la-lg except that the products were not poured into toluene. Diols 2a-2g were resinous solids which solidified on standing. 

The epoxidalion is generally conducted in iwo steps (11 the polyol is added to cpichlorohydrin in the presence of a Lewis acid catalyst (stannic chloride, boron irifluoride) to pruduce the chlorollydrin intermediate, and (2] the intermediate is dchydrohalogenaled with sodium hydroxide iu yield the aliphatic glycidyl ether. Solid epoxy resins are prepared by the Taffy or Advancement processes. 

The slurry is pumped into another stock chest, where wax in emulsion form, usually about 0.5—1.0% wax-to-fiber weight, and 1—3% PF resin are added. PF resin is also added on the basis of resin solids-to-dry fiber. Then a small amount of alum is added, which changes the pH (acidity) of the slurry, causing the resin to precipitate from solution and deposit on the fibers. Resin is required in greater quantity than in the Masonite process because only light bonding occurs between fibers prepared in a refiner. The fiber slurry is then pumped to the headbox of a Fourdrinier mat former, and from this point the process is similar to the Masonite process. 

Properties of the HDA boards prepared from the activated substrate may be compared to the phenol-formaldehyde (PF) boards prepared using 6 resin solids. Comparison may also be made to the property requirements from commercial standard CS 236-66, type 2 medium density (below 0.8 g/cc), Class 1 particleboard fabricated using durable and highly moisture resistant and heat resistant binders suitable for interior and certain exterior applications. Specifications of this class of particleboard, generally prepared from PF resins, are MOR, minimum = 2,500 psi M0E, minimum =... 

Resin Preparation. All phenolic resins were prepared in the laboratory. Resin preparations were replicated one time. To prepare each resin, all phenol and water were placed in a reaction kettle. The formaldehyde was added in three steps 1) total formaldehyde less 1 mole of formaldehyde was added at the beginning 2) the balance was divided into two equal parts (i.e., 0.5 mole each), one of which was added 1 hour after the reaction began and 3) the remainder of formaldehyde was added 20 minutes later. The sodium hydroxide was added as catalyst in four steps (i.e., four equal parts at 10-minute intervals). To initiate the reaction, the mixture was heated and maintained at 75 °C. All reactions were terminated at the end of 100 minutes. Gel time, pH, viscosity, solid content, and specific gravity were determined. The general conditions for resin preparation were ... 

Presintered resins are prepared by melting as-polymerized PTFE, cooling the melt, and disintegrating the resin back into small particles. The average particle size of these resins is several hundred microns, and their melting point is reduced from 342°C (657°F) to 327°C (621°F). The powder flow is improved by this process considerably, and the presintered products are particularly suitable for ram extrusion of thin-walled tubes and thin solid rods. 

Duplicate 12 mm thick three layers particleboard 600 mm x 300 mm in dimensions were prepared in the laboratory using 7 Z UF resin solids total on oven dry pine wood chips. The glue mix used was as follows ... 

For cleavage of the aldehyde, fhe resin (3.43 g) was stirred with dioxane/ dilute HCl (1 1 40 mL) for 48 h at rt. The resin was fhen filtered off and washed with water (six times), acetone (once), efhanol (three times), and diethyl ether (three times). The aqueous filtrate was extracted three times wifh diethyl ether. The combined ethereal extracts were washed with water, dried over Na2SO4, and concentrated to give a solid, preparative TLC of which yielded 86% of fhe desired aldehyde. 

Films containing the diamic acid additives were prepared by dissolving 3-15 weight percent (based on resin solids) of the additives into the polyamic acid solutions, then casting and curing as above. 

The potential applications for conducting polymers are enormous and this has stimulated a large amount of research into this area. Not surprisingly, solid-state NMR spectroscopy has been applied to study these amorphous, insoluble and in many cases crosslinked materials [24]. Looking at the CP/MAS spectra of a series conducing polyacenic polymers, some of which were doped with iodine, it was possible to see the effect of the halogen upon conductivity. These resins were prepared by a conventional procedure for the preparation a Novolak-type phenol-formaldehyde resin. After synthesis, the phenol-formaldehyde resin were dissolved and solutions were cast as a film and heat treated to between 590-670°C in a N2 atmosphere to form the polyacenic film. The electrical conductivity of the films was shown to increase... 

Following the work of Ellis (9) a resin was prepared by the interaction of sulfur monochloride and 2,3-xylenol. This resin (9 g) was added to molten sulfur (27 g), and on cooling a brittle solid was obtained. 

A benzyl halide solid support If (Table 1) has been reported [77] that affords anchoring groups which are less labile than trityl anchors Ib-le but more labile than anchors to chloromethyl-PS (la). Resin If has been used to prepare amides and sulfonamides by reaction with an amine followed by acylation or sulfonylation, respectively, and cleavage using 95% TFA. When the same reaction sequence was conducted on an analogous resin Ig prepared from Tentagel AC (acid-cleavable linker), the products could be cleaved under milder conditions (5% TFA) because of the greater stability... 

The oxidation-reduction method, developed initially by Mukaiyama et al. [133] and related to the previously described organophosphorus methods, has permitted a variety of important solid-phase applications. The mechanism of the activation is complex and involves the oxidation of the triaryl/ alkyl-phosphine to the oxide as well as reduction of the disulfide to the mercapto derivative. However, different active species, such as 81 (Fig. 11), the 2-pyridyl thioester, or even the symmetrical anhydride, have been postulated to form. For the intermediate 81, the peptide bond formation may proceed through a (cyclic transition state. The method has been used for conventional stepwise synthesis [134], acylation of the first protected amino acid to a hydroxymethyl resin, and to achieve segment condensation on a solid support in the opposite direction (N C) [135,136]. Lastly, it has been used for efficient grafting of a polyethylene glycol (molecular weight 2000) derivative to an aminomethyl resin to prepare PEG-PS resins [137]. 

Our approach has been to synthesize the dleplsulflde resin corresponding to the normal blsphenol A type dlepoxlde resins. A polyamide type curing agent (Versamlde 140) was used because of our particular Interest In orthopedic adhesives, l.e. "bone cement". Some of the properties were therefore tailored to be optimum near body temperature. We have found very little prior literature on dleplsulflde resins. As prepared, the dleplsulflde resin analog of DGEBA Is a crystalline solid which must be heated above Its melting temperature for reaction. Charlesworth (2) has reported mechanical relaxation behavior of epoxy-episulfide poly-... 

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