Gregory process

Codeine may be isolated from opium by the Gregory process [9], in which the concentrated aqueous opium extract is treated with a concentrated solution of calcium chloride, when calcium meconate, lactate, and sulphate are precipitated and removed, when the filtrate on concentration deposits the Gregory salt , a mixture of the hydrochlorides of morphine and codeine. This is purified, dissolved in water, and the morphine precipitated by ammonia, when the codeine remains in solution from which it is extracted by benzene, or the solution concentrated to the point at which a mixture of codeine hydrochloride and ammonium chloride separates. Other procedures for the isolation of codeine are available [7, 8, 10-22 inc.], critical summaries of which are given by Kanewskaja [23] and Barbier [24], Codeine may be separated from neopine (see Chap. VII) through the sulphate [25] and from morphine by chromatography [26-29]. Most of the codeine used commercially is prepared by the methylation of morphine (see below). 

The processes used in the manufacture of morphine are believed to be still based on that described by the Scottish chemist Gregory,in 1833, with improvements devised by Anderson. A description has been published by Schwyzer, who also deals with the manufactme of codeine, narcotine, cotarnine, and the commercially important morphine derivatives, diamorphine (diacetylmorphine), and ethylmorphine (morphine ethyl ether). More recently Barbier has given an account of processes, based on long experience in the preparation of alkaloids from opium. Kanewskaja has described a process for morphine, narcotine, codeine, thebaine and papaverine, and the same bases are dealt with by Chemnitius, with the addition of narceine, by Busse and Busse, and by Dott. It is of interest to note that a number of processes for the extraction and separation of opium alkaloids have been protected by patent in Soviet Russia. ... 

Papaverine, C20H21O4N. This alkaloid, first obtained by Merck, occurs in the mixture precipitated by ammonia from the mother liquors of opium extract from which morphine and codeine have been separated in Gregory s process, and methods for its isolation from this mixture have been published by Hesse and others. The alkaloid may be purified by conversion into the acid oxalate, B. H2C2O4, m.p. 196° or 201-5-202°, which is nearly insoluble in alcohol. 

Codeine, C18H21O3N. This alkaloid was isolated from opium by Robiquet in 1833. It occurs in opium to the extent of 0-1 to 3 per cent., and is isolated therefrom as the hydrochloride along with morphine hydrochloride in the first stage of Gregory s process. It is a methyl ether of morphine and is usually made from the latter by methylation, for which there are numerous patents. An extensive series of ethers of morphine and its isomerides, including ethers of the alcoholic hydroxyl group (Aeterocodeines) has been prepared by Faris and SmaU. ... 

Thebaine, CjgHgiOgN. This base, which occurs in opium to the extent of 0-1 to 1 per cent., was first obtained by Pelletier and Thiboumery, who regarded it as isomeric with morphine, and named it paramorphine. It was examined by Kane, who first called it thebaine, and by Anderson, who described a method of isolation and provided the formula given above. It remains in the mother liquor after the removal of morphine and eodeine hydrochlorides in Gregory s process, and in Hesse s method of isolating it from this source is obtained as the acid tartrate. This is crystallised from hot water, and the alkaloid regenerated from it is reerystallised from dilute alcohol, from which it separates in leaflets, or from dry alcohol in prisms, m.p. 193°, — 218-6° (EtOH) or — 229-5°... 

Gregory, I., 1984b. Flocculation and filtration of colloidal particles. In Emergent process methods for high temperature ceramics, Eds. R.F. Dvais etai. Plenum Press, London p. 59. 

Gregory, and it still applies - if you take a radio and delete a transistor from it and the result is that instead of a symphony you get a howl, you can t conclude that the function of the transistor was a howl suppressor. That is one of the major problems of knock-out studies, that they are compounded by the fact that if you take a transistor out of a radio it can t self-repair. In a developing animal, if you take out a gene, then what you get is compensatory plasticity, other processes taking over as well. So the interpretation of any of those knock-out studies is immensely complicated. 

Studies on orthokinetic flocculation (shear flow dominating over Brownian motion) show a more ambiguous picture. Both rate increases (9,10) and decreases (11,12) compared with orthokinetic coagulation have been observed. Gregory (12) treated polymer adsorption as a collision process and used Smoluchowski theory to predict that the adsorption step may become rate limiting in orthokinetic flocculation. Qualitative evidence to this effect was found for flocculation of polystyrene latex, particle diameter 1.68 pm, in laminar tube flow. Furthermore, pretreatment of half of the latex with polymer resulted in collision efficiencies that were more than twice as high as for coagulation. 

Flocculation rate limitation. The adsorption step was rate limiting for the overall flocculation process in this system. Polymer adsorption rate measurements for dispersed systems reported in the literature (2,26) do not lend themselves to direct comparisons with the present work due to lack of information on shear rates, flocculation rates, and particle and polymer sizes. Gregory (12) proposed that the adsorption and coagulation halftimes, tA and t, respectively, should be good indications of whether or not the adsorption step is expected to be rate limiting. The halftimes, tA and t, are defined as the times required to halve the initial concentrations of polymer and particles, respectively. Adsorption should not limit the flocculation rate if... 

If adult odor preferences are in fact influenced by early olfactory experience, then chemosensory processing must be functional early in rodent development. Indeed, the chemosensory systems develop very early in rodents (Alberts 1976 Astic and Saucier 1981), and chemosensory processing appears to be functional both prena-tally (Pedersen and Blass 1982 Stickrod, Kimble and Smotherman 1982) and peri-natally, as evidenced by behavioral responses to odors (Devor and Schneider 1974 Gregory and Bishop 1975 Leon and Moltz 1971 Porter and Etscorn 1974). For example, Syrian hamster pups display behavioral preferences for different types of artificial odorants as early as postnatal day 4 (Devor and Schneider 1974). These data suggest that young rodents are able to both process and respond to odors present in their early environment. 

F. McClellan andB.R. Kowalski, Process Analytical Chemistry, Blackie Academic and Professional, London, 1995. C.H. Gregory, H.B. Appleton, A.P. Lowes and F.C. Whalen, Instrumentation and Control in the German Chemical Industry, British Intelligence Operations Subcommittee Report 1007, June 1946. 

Gregory, R.T Criss, R.E. 1986. Isotopic exchange in open and closed systems. In Stable isotopes in high temperature geological processes. Reviews in Mineralogy 16, Mineralogical Society of America, Washington, 91-127. 

Protein subunits will partially dissociate from crystalline ferritin in dilute salt solutions to yield a non-crystallizable ferritin. The non-crystallizable ferritin, in turn, in the presence of apoferritin appears to pick up protein subunits and by action yield crystalline ferritin molecules. The scheme for this process is shown in Fig. 6. The salient feature of this scheme is the initial formation of an iron micelle from soluble iron chelates which is then stabilized by protein subimits S5uithesized by the tissue (726). Harrison and Gregory 127) have used glacial acetic acid to dissociate apoferritin completely. When the pH is adjusted to 4 in the presence of thiol compoimds, apoferritin is rapidly formed, indicating strong subunit interaction. 

Halliday R, Gregory K, Naylor H, et al Beyond drug effects and dependent variables the use of the Poisson-Erlang model to assess the effects of d-amphetamine on information processing. Acta Psychologica 73 35-54, 1990 Hallman M, Bry K, Hoppu K, et al Inositol supplementation in premature infants with respiratory distress syndrome. N Engl J Med 326 1233-1239, 1992 Hamik A, Peroutka S MCPP interaction with neurotransmitter receptors in human brain. Biol Psychiatry 25 569-575, 1989... 

What we have covered in this chapter barely scratches the surface of a vast area of applications of colloidal phenomena in chemical and materials processing industries and in environmental and other operations. There are many fundamental, as well as practical, problems in the above topics (especially ones involving polymers, polyelectrolytes, and polymer-colloid and polymer-surfactant mixtures) that are currently areas of active research in engineering, chemistry, physics, and biology. Some of the references cited at the end of this chapter contain good reviews of topics that are extensions of what we have covered in this chapter (see, e.g., Elimelech et al. 1995, Hirtzel and Rajagopalan 1985, Israelachvili 1991, Gregory 1989, and O Melia 1990). 

Gregory and Style67 produced CH2 by photolysis (mainly 3100 A.) of CH2I2, although they were not certain if the primary process was... 

Codein is obtained from the last filtrate in Gregory and Robertson s process for preparing morphia. As... 

Figure 19.12. Batch parametric processing of solid-liquid interactions such as adsorption or ion exchange. The bottom reservoir and the bed interstices are filled with the initial concentration before pumping is started, (a) Arrangement of adsorbent bed and upper and lower reservoirs for batch separation, (b) Synchronization of temperature levels and directions of flow (positive upward), (c) Experimental separation of a toluene and n-hcptane liquid mixture with silica gel adsorbent using a batch parametric pump. (Reprinted from Wilhelm, 1968, with permission of the American Chemical Society), (d) Effect of cycle time t on reservoir concentrations of a closed system for an NaCl-H20 solution with an ion retardation resin adsorbent. The column is initially at equilibrium with 0.05M NaCl at 25°C and a = 0.8. The system operates at 5° and 55°C. [Sweed and Gregory, AIChE J. 17, 171 (1971)J.

Gregory (Ref. G6) is a very comprehensive source specific to the industrial and commercial applications of chemicals. It includes a three page list of the uses of nitric acid. Similar information is presented for many other chemicals in this book. The one fault of this source is that it is 50 years old In that period many process technologies have changed and the applications list, whilst very comprehensive, tends to be dated. 

Motion and color are processed by different cortical areas. A difference in the luminance of a moving stimulus is required for coherent motion perception (Ramachandran and Gregory 1978). Cells found in V3 respond to lines of different orientation and also to motion (Tovee 1996). They do not respond to color. V3 is believed to process dynamic form. Some cells of V3 are able to discount the movement of the eye. They only respond to a stimulus that moves relative to the eye. These cells also receive information about the eye position (Zeki 1999). Cells in V3 are connected to layer 4B of VI. V3 is also connected to the thick stripes of V2. 

Gregory, J. Stability and Flocculation of Suspensions in Processing of Solid-Liquid Suspensions, Shamlou, P.A. (Ed.), Butterworth-Hei-nemann Boston, 1993, pp. 59-92. 

Gregory McMillan, formerly an engineering fellow in process control for the Monsanto Chemical Company, approached the subject differently. His very entertaining presentation entitled, Can You Say Process Interlocks at an AIChE Loss Prevention Symposium was written as a parody of a popular youngster s TV show. [27]... 

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