Transfer to a modifier

Modifiers are species that contain a labile atom (most usually hydrogen or halogen) which can be abstracted by the propagating chain. 

Propagation of the chain is terminated and the radical is transferred to the modifier. 

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The solution of sodium methyl sulfide in absolute alcohol is transferred to a 3-I. three-necked flask, which is placed on a steam bath and fitted with a dropping funnel, a reflux condenser, and a mechanical stirrer. The solution is heated until the alcohol begins to boil. Heating is then discontinued and 302 g. (3.7s moles) of ethylene chlorohydrin (Note 5) is added dropwise with efficient stirring over a period of about two hours (Note 6). The reaction mixture is concentrated by distilling as much of the alcohol as possible on the steam bath. The mixture is then allowed to cool and the sodium chloride removed by filtration. The flask is rinsed, and the sodium chloride washed with three loo-cc. portions of 95 per cent alcohol. The combined filtrate and washings are concentrated on the steam bath under reduced pressure until no further distillate passes over. The residue is then transferred to a modified Claisen flask (Org. Syn. Coll. Vol. i, 125) and fractionally distilled under reduced pressure. The yield is 238-265 g. (74-82 per cent of the theoretical amount based on the sodium used) of a product boiling at 68-7o°/20 mm. 

Most of the alcohol is removed by distillation (one and one-balf hours) on a steam bath and the residue transferred to a modified Claisen flask and distilled. The fraction boiling below 50° at 20 mm. (Note 6) is removed with the aid of a water pump and the residue distilled using an oil pump (at 3 mm. pressure) (Note 7). The portion boiling at 105-108° at 3 mm. (Note 8) is collected as di-/S-carbethoxyethylmethylamine (Note 9) it amounts to 519-550 g. (83-86 per cent of the theoretical amount) (Note xo). 

In a 3-I. round-bottomed flask fitted with a 3-ft. indented column to which is attached a condenser set for downward distillation are placed 321 g. (3 moles) of methylaniline, 300 g. of formic acid (85-90 per cent), and 1800 cc. of toluene (Note 1). The solution is distilled slowly. As long as the azeotrope containing water is present, the temperature of the vapor is 87-88° when the water has been removed, the temperature rises to 108-110° (Note 2). The distillation is continued until approximately 1500 cc. of toluene has been collected (five to six hours). The residue is then transferred to a modified Claisen flask (Org. Syn. Coll. Vol. 1, 125) and distilled in vacuo, the portion boiling at 114-121° at 8 mm. being collected. This has a freezing point of 13.6-13.7° d i-5S3 I SSS- The yield is 380-393 g. (93-97 per cent of the theoretical amount). This product is satisfactory for the preparation of aldehydes (p. 11). Upon redistillation it boils at 117-121° at 8 mm., 130-132° at 22 mm. The freezing point and refractive index are unchanged. 

The product is transferred to a modified Claisen flask (Note 4) and distilled under reduced pressure, heat being supplied by an oil bath (Note 5). Most of the thionyl chloride distils at room temperature. The yield of almost colorless product distilling at 64-66°/20 mm. (Note 6) is 122-143 g. (71-83%) 1.451. 

Several so-called hyphenated techniques have been developed, where the developed TLC plate is transferred to a modified spectrometer to record in situ the Fourier transform infrared, surface enhanced Raman, or mass spectra of the separated zones. This way more detailed structural information can be obtained to complement the data from densitometric evaluation. A true hyphenation is the direct application of the eluate from a microbore HPLC column onto an HPTLC plate, which is then developed by AMD. 

Analogously, the influence of the pressure on the chain transfer to a modifier can be described by the expression... 

After all of the cyclohexylbromopropene has been run in, heating is continued for about two hours, the mixture is cooled and 500 cc. of ether is added. This mixture is poured on 1.5 kg. of cracked ice in a 5-I. flask and then acidified with 280 cc. of concentrated hydrochloric acid. The ether layer is separated, dried over calcium chloride and transferred to a i-l. modified Claisen flask (Org. Syn. 1, 40) for distillation. The ether is distilled at ordinary pressure and then the cyclohexylpropine under diminished pressure. The product boiling up to ii5°/2o... 

In a 1-L rbf attached to a Dean-Stark trap, equipped with a reflux condenser is placed distilled aniline (1, 46.5 g, 45.5 mL, 0.5 mol), commercially available ethyl acetoacetate (5, 65 g, 63.5 mL, 0.5 mol), benzene (100 mL) and glacial AcOH (1 mL). The flask is heated at about 125 °C, and the water which distills out of the mixture with the refluxing benzene is removed at intervals. Refluxing is continued until no more water separates (9 mL collects in about 3 hrs) and then for an additional 30 min. The benzene is then distilled under reduced pressure, and the residue is transferred to a 125 mL modified Claisen flask with an insulated column. The flask is heated in an oil or metal bath maintained at a temperature not higher than 120 °C while the forerun of 1 and 5 is removed and at 140-160 °C the product distills giving 78-82 g, 76-80% yield of 6. 

After standing about three hours, the diphenylamine hydrochloride is filtered and washed with benzene (Note 10). The benzene is distilled from the filtrate (Note n) and the residual triphenylamine is transferred to a 500-cc. modified Claisen flask (Org. Syn. 1, 40) and distilled under reduced pressure. The first fraction consists of some benzene, then the temperature rises rapidly and a few cubic centimeters of deeply colored distillate comes over just before the amine fraction, which is collected at i95-205°/io-i2 mm. The distillate is a yellow liquid which soon solidifies to a light yellow solid. The side arm of the distilling flask should be of rather large bore (about 10 mm.) to prevent clogging by the amine which solidifies. The crude product weighs 220-235 g. and melts at 120-124°. 

While still warm, the reaction mixture is transferred to a 250-cc. modified Claisen flask (Org. Syn. Coll. Vol. 1, 1941, 130) fitted fox distillation under reduced pressure. Any hydrogen bromide remaining in the reaction mixture is removed by heating at 120° under the vacuum of a water pump. The product is then distilled "under reduced pressure. The fore-run of less than 15 g. 

In a modified system in which a suspension of solids is conveyed through the heat transfer section, the heat transfer coefficient is greater than that obtained with liquid alone, though lower than that obtained at the same concentration in a fluidised system. Similar conclusions have been reached by Jepson, Poll, and Smith(95) who measured the heat transfer to a suspension of solids in gas. 

In this pull-down assay, the enzymatic reaction is carried out completely in solution. Samples taken from the reaction mixture are then transferred to a SAM-modified MALDI target, on which the remaining substrate and the reaction product are selectively immobilized. Subsequent to the extraction of the analytes, the target is rinsed, treated with matrix, and MALDI-MS analysis is carried out. A major advantage of this assay scheme is that the inherent danger of negative influences on the reaction kinetics, which may be caused by immobilization of the substrate as in standard SAMDI-MS-based assay formats, is circumvented. Additionally, by selective extraction of the analytes of interest and removal of the other... 

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