Double Centralizer

The following lemma is often referred to as Double Centralizer. 

GE has doubled central R D staff over the past eight years, but all of the new jobs have been located offshore, in India, China, and Germany the latter two locations were built in the last three years. Note that Germany is at least as expensive as the U.S. in which to conduct R D, so it cannot be said cost is the primary incentive underlying GE s decision to build this new offshore site (unless there were undisclosed German government financial incentives involved). 

Fit the central neck of a 1-litre three-necked flask with an efficient double surface condenser and close the two side necks with corks (1). Place 52 g. (59-5 ml.) of ethyl n-valerate (Section 111,104) and 800 ml. of super-diy ethyl alcohol (Section 11,47, 5) (2) in the flask. Add 95 g. of clean sodium in small pieces through one of the apertures at such... 

P-Hydroxy-a-naphthaldehyde, Equip a 1 litre three-necked flask with a separatory funnel, a mercury-sealed mechanical stirrer, and a long (double surface) reflux condenser. Place 50 g. of p-naphthol and 150 ml. of rectified spirit in the flask, start the stirrer, and rapidly add a solution of 100 g. of sodium hydroxide in 210 ml. of water. Heat the resulting solution to 70-80° on a water bath, and place 62 g. (42 ml.) of pure chloroform in the separatory funnel. Introduce the chloroform dropwise until reaction commences (indicated by the formation of a deep blue colour), remove the water bath, and continue the addition of the chloroform at such a rate that the mixture refluxes gently (about 1 5 hours). The sodium salt of the phenolic aldehyde separates near the end of the addition. Continue the stirring for a further 1 hour. Distil off the excess of chloroform and alcohol on a water bath use the apparatus shown in Fig. II, 41, 1, but retain the stirrer in the central aperture. Treat the residue, with stirring, dropwise with concentrated hydrochloric acid until... 

An sp3-sp2 or sp -sp - single bond where the atom con-nected to the central sp (sp - ) atom is another sp (sp - ) atom, as in the H-C-C-double bond 0 torsion of acetic acid, is described by the MM-t parameters of acetic acid, Vl=-0.167 kcal/mol and V3=-0.1 kcal/mol. 

Apianar sp -sp single bond or planar sp -sp - single bond (for example, the central bond of butadiene, with isolated double bonds, or phenyl amine, where the nitrogen is sp hybridized) is described by a two-fold barrier, V2=5 kcal/mol. 

In pharmaceutical appHcations, the selectivity of sodium borohydride is ideally suited for conversion of high value iatermediates, such as steroids (qv), ia multistep syntheses. It is used ia the manufacture of a broad spectmm of products such as analgesics, antiarthritics, antibiotics (qv), prostaglandins (qv), and central nervous system suppressants. Typical examples of commercial aldehyde reductions are found ia the manufacture of vitamin A (29) (see Vitamins) and dihydrostreptomycia (30). An acyl azide is reduced ia the synthesis of the antibiotic chloramphenicol (31) and a carbon—carbon double bond is reduced ia an iatermediate ia the manufacture of the analgesic Talwia (32). 

The compounds of this article, ie, ftve-membered heterocycles containing two adjacent nitrogen atoms, can best be discussed according to the number of double bonds present. Pyrazoles contain two double bonds within the nucleus, imparting an aromatic character to these molecules. They are stable compounds and can display the isomeric forms, (1) and (2), when properly substituted. Pyrazoles are scarce ia nature when compared to the imidazoles (3), which are widespread and have a central role ia many biological processes. 

The central carbon atom is derived from an aromatic aldehyde or a substance capable of generating an aldehyde during the course of the condensation. Malachite green is prepared by heating benzaldehyde under reflux with a slight excess of dimethyl aniline in aqueous acid (Fig. 2). The reaction mass is made alkaline and the excess dimethylaniline is removed by steam distillation. The resulting leuco base is oxidized with freshly prepared lead dioxide to the carbinol base, and the lead is removed by precipitation as the sulfate. Subsequent treatment of the carbinol base with acid produces the dye, which can be isolated as the chloride, the oxalate [2437-29-8] or the zinc chloride double salt [79118-82-4]. 

The principle of double entry dates from the fifteenth century and is based on the premise that eveiy transaction involves a giver and a receiver of value. Double entiy requires that each transaction be entered into two accounts, the convention being that the account of the giver is credited and the account of the receiver is debited with the same amount of money, as noted in the journal. For convenience, each account is divided centrally, and the debit items are entered on the right-hand side. It is also usual to provide a cross-reference to the journ entiy so that errors and omissions can be checked. 

Notice that in B-DNA the central axis of this double helix goes through the middle of the base pairs and that the base pairs are perpendicular to the axis. 

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