Flasks resin reaction

A sample of peptide-resin (1.0g, 0.23 mequiv-g-1) was placed in a 10-mL reaction vessel, and the resin was washed with CH2C12 (5 x) The terminal Boc protecting group was removed and the resin was neutralized by standard procedures. In a separate flask, 2,2 -bipyridyl-5-carboxylic acid (201 mg, 1.0 mmol), HOBt (135.1 mg, 1.0 mmol), and DMAP (30 mg, 0.25mmol) were dissolved in DMF (5.0mL). To this soln, DIC (157 p,L, 1.0 mmol) was added and the mixture stirred at rt for 30 min. The mixture was then transferred to the peptide-resin reaction vessel and allowed to react for 3-4 h with constant shaking. The resin was then washed with DMF (5 x) and CH2C12 (5 x) and dried in vacuo. 

A total of 924 MacroKans (each containing 300 mg of resin 28 with a loading of 1.2 mmol/g) was placed into a 12-liter three-necked round-bottom flask fitted with an overhead stirrer and a heating mantle. DMF (6 liters) and tin dichloride dihydrate (750.5 g, 3326.4 mmol) were added to the flask. The reaction was stirred at 50° overnight. For workup, the reaction solution was drained. The resin was then washed with DMF, aqueous THF, THF, DCM, and diethyl ether. The MacroKans were dried overnight with a stream of nitrogen gas. 

Preparation of 5-[bis/2-Hydroxyethyl)Amino] Uraci/ 20 grams (0.157 mol) of 5-amlno-uracil was mixed with 350 ml of water, 23 ml of glacial acetic acid, and 160 ml of ethylene oxide in a one-liter flask immersed in an ice bath. The reaction mixture was stirred and allowed to come to room temperature slowly (as the ice melted), and stirring was continued for two days. A clear solution resulted to which was added 250 ml of water and 60 grams of Dowex-50 in the acid form. The mixture was stirred for 15 minutes, and the resin was collected on a filter. It was washed with water and the crude 5-[bis(2.hydroxy-ethyl)amino] uracil was eluted with a 10% aqueous solution of ammonium hydroxide. 

Because hydrolytic reactions are reversible, they are seldom carried out in batch wise processes [26,28,36,70]. The reactor is usually a double jacket cylindrical flask fitted with a reflux condenser, magnetic stirrer, and thermometer connected with an ultrathermostat. The catalyst is added to the reaction mixture when the desired temperature has been reached [71,72]. A nitrogen atmosphere is used when the reactants are sensitive to atmospheric oxygen [36]. Dynamic methods require more complicated, but they have been widely used in preparative work as well as in kinetic studies of hydrolysis [72-74]. The reaction usually consists of a column packed with a layer of the resin and carrying a continuous flow of the reaction mixture. The equilibrium can... 

N-Methylimidazole is then removed from the reaction mixture with Amberlyst 15 ion exchange resin (Note 9) using the following procedure. To a 2-cm diameter column equipped with a glass frit (Note 1) is added 7 g of Amberlyst 15, which is rinsed with 25 mL of methylene chloride. The reaction mixture is added and the resin mixture is rinsed with 50 mL of methylene chloride. The filtrate is collected in a 250-mL flask (Note 10) and the solvent is removed on a rotary evaporator to afford 1.63-1.66 g (96-98%) of the desired ester 1 as a deep red foam. HPLC analysis showed a purity of 98% (Notes 11, 12, 13, 14). 

In preparing elastomers by the two-step procedure, the entire quantities of LHT-240 and TDI were mixed in the resin flask under high-purity nitrogen for 2 hours at 50°C. Even without catalyst, this period was sufficient to obtain complete reaction, or essentially so, because of the relatively high reactivity of the para isocyanate group in the TDI. The... 

The resin-bound salicylic esters were suspended in N,N-dimethylformamide (DMF) and placed in an Erlenmeyer flask within a domestic microwave cavity. After microwave irradiation for 4—6 min (1 min cycles), the reaction mixture was allowed to cool to ambient temperature and the resin was collected by fdtration and washed with methanol and dichloromethane. The desired compounds were subsequently cleaved with trifluoroacetic acid in dichloromethane. Removal of the solvent by evap-... 

A. l-Phenyl-2,2,2-lrichloroethanol. In a 1-1. round-bottomed-flask fitted with a mechanical stirrer, a thermometer, and a powder funnel is placed a solution of 212 g. (2.00 moles) of freshly distilled benzaldehyde in 400 g. (270 ml., 3.35 moles) of chloroform. The mixture is cooled in an ice bath, and 123 g. of commercial powdered potassium hydroxide is added with stirring at such a rate that the temperature of the solution does not exceed 45° (1-1.5 hours). The reaction mixture is stirred and kept at 40-50° for an additional hour and then poured into a solution of 60 ml. of sulfuric acid in 3 1. of water. The resulting two-phase mixture is transferred to a separatory funnel and extracted with three 250-ml. portions of chloroform (a small amount of insoluble, black resinous material is discarded). The combined organic layers are washed with three 100-ml. portions of aqueous 10% sodium carbonate, dried over anhydrous magnesium sulfate, and filtered into a 1-1. flask. The solvent is removed under reduced pressure on a hot water bath. The residue is transferred to a 250-ml. flask and distilled under reduced pressure to give l-phenyl-2,2,2-trichloroethanol, b.p. 155-165° (26 mm.), 90-100° (0.5 mm.) (Notes 1 and 2). The yield is 170-180 g. (38-40%). 

ArgoGel-MB-CHO resin (366 mg, 0.42mmol/g substitution) was placed into an Ace pressure tube (note 5). Trimethyl orthoformate (TMOF 5 mL) was added to the flask along with the primary amine (10 equiv.). The tube was capped and heated for 2h at 70°C in a rotating oven (note 6), and cooled. The TMOF solution was removed with the use of a filtration cannula, and the entire process was repeated. The resin was washed with TMOF (5 mL, lx) and anhydrous methanol (5 mL, 3 x) Anhydrous methanol (5 mL) was added to the resin, followed by the addition of sodium borohydride (133 mg, 20 equiv.). After vigorous gas evolution had ceased, the tube was capped and agitated for 8 h at room temperature. The resin was then transferred to a polypropylene reaction vessel and washed with methanol (5mL, 3 x), methanol water (1 1, 5mL, 3 x), DMF water (1 1, 5mL, 3 x), DMF (5mL, 3 x), and methylene chloride (5 mL, 3 x). 

To 11.Og (12.3 mmol) of Wang resin (Note 1) in an oven-dried, solid-phase reaction flask (Note 2) equipped with an overhead stirrer and a nitrogen line attached to a bubbler was added 100 mL dichloromethane. The resultant slurry was allowed to stir for... 

To product 1 (11.58g [calculated], 11.39 mmol) in the reaction flask from the above procedure was added 50 mL methyl sulfoxide and 7.5 mL (68.3 mmol) benzylamine (Note 6) and the slurry was allowed to stir for 24 h at room temperature. The resin was filtered, retreated with 50 mL methyl sulfoxide and 7.5 mL (68.3 mmol) benzylamine, and stirred for another 24h at room temperature. The reagents were removed by suction filtration in the vessel, the resin was washed three times each with 50 mL... 

To a slurry of product 4 (13.07 g [calculated], 8.14mmol) in lOOmL DMF in the reaction flask from the last procedure was added 5.85 mL (62.1 mmol) acetic anhydride (Note 8) and 8.66 mL (62.1 mmol) triethylamine. The slurry was stirred for 3 h at room temperature. The resin was filtered and washed three times each with 50 mL portions of each of the following solvents A, A-dimcthyl acetamide, methanol, and dichloromethane. After drying the resin by allowing nitrogen to flow through the reaction... 

As first practiced by Geysen and Houghton, the preparation of combinatorial libraries produced discrete compounds of known identity through a technique known as "spatial separation," which simply means that individual compounds in the library are produced discretely and are not mixtures. Such spatially addressable compound sets are produced in such a way as to keep separate the reaction flasks or resin beads containing the individual components of the library and perform bioassays on the discrete compounds, one at a time. Thus, if the "history" of the reaction conditions performed in each flask or on each solid support, the identity of the compounds produced is known, without resort to structure elucidation techniques. Initially, this technique, after typically an extensive reaction development stage, allowed the preparation of between 10 and 1000 discrete combinatorial products. 

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