Bases for Preparations

Because carbonyl compounds are only weakly acidic, a strong base is needed for enolate ion formation. If an alkoxide such as sodium ethoxide is used as base, deprotonation takes place only to the extent of about 0. l% because acetone is a weaker acid than ethanol (pKa - 16). If, however, a more powerful base such as sodium hydride (NaH) or lithium diisopropylamide ILiNO -CjHy ] is used, a carbonyl compound can be completely converted into its enolate ion. Lithium diisopropylamide (LDA), which is easily prepared by reaction of the strong base butyllithium with diisopropylamine, is widely used in the laboratory as a base for preparing enolate ions from carbonyl compounds. 

D.M. Lowe, M.I. Gusmann and J.G. McCarty, preprints 6th Int. Symp. on Scientific Bases for Preparation of Heterogeneous Catalysts , September 5-8 1984, Louvain-la-Neuve Belgium, Vol. 2, p.39. 

The Fischer s bases, 2-alkylidene-l,3,3-trisubstituted indolines, which may be further substituted in the indoline ring, are the most versatile and useful bases for preparing spiropyrans. For convenience, the name Fischer s base will be used hereafter in the general sense indicated above, as well as for the specific compound 2-methylene-l,3,3-trimethylindoline. Substituents in the 1- and 3-positions are methyl unless otherwise specified thus 3-phenylFischer s base denotes the 1,3-dimethyl-3-phenyl compound. 

A concentrated base for preparing nonionic softeners, lubricants and napping assistants... 

ApM maeier and 0 Bock> Scientific Bases for Preparation of Heterogeneous Catalyst 2nd Inter. Syaposlum EB, Sept 4-7, Belgium, (I978i M- Boudart and W-C- Cheng J Catal 106, (1987), 134 A G Bhattacharya J.Chem.Far.Trans1, 7b (1980), 126 Voorhoeve J.Catal, 3, (1971),... 

Sodium hydroxide is the most common base for preparing standard solutions, although potassium hydroxide and barium hydroxide are also encountered. Because none of these is obtainable in primary-standard purity, standardization of these solutions is required after preparation. 

In homeopathy (see the discussion of this type of medicine in chapter 4), a dilute alcohol/water extract is used as a base for preparing other medicines. This preparation is called the mother tincture and it is made in a 1 10 dilution with the fresh ripe berries. The directions for its manufacture in the Homeopathic Pharmacopoeia are as follows ... 

Prisavon. [Unichema] Soap bases for preparation of specialty soaps, toilet soap, household soap bars, soap powders, industrial and liq. soqts. 

R.A.Shkrabina, N.A.Koryabkina, O.A.Kirichenko, V.A.Ushakov, F.Kapteijn and Z.R.Ismagilov, Scientific Bases for Preparation of Heterogeneous Catalysts 6th International Symposium Prepr. V.3, Louvain la Neuve,... 

Concentrated base for preparation of premium fabric softeners, anti-static treatments, and hair conditioner products. 

Widely used cationic base for preparation of opaque and pearlescent creme rinse conditioners. Provide excellent anti-stat, comb-out, and detangling properties in formulated hair care products. 

Concentrated surfactant base for preparation of elegant shampoos and cosmetic products. Produces luxurious creamy lather in formulated personal care systems. 

Excellent bases for preparation of high viscosity, formulated products. 

Cosmetic grade surfactant base for preparation of high foaming shampoo, handsoap, and light duty detergent systems. Displays excellent stability over wide pH ranges. 

Trimm DL. In Delmon B, Jacobs PA, PoceletC (eds.) Preparation of Catalysts II-Scientiflc Bases for Preparation of Heterogeneous Catalysts, translated by Wan Ren, Beijing Chemical Industry Press, 1985, 6-8. 

The iodimetric method of assay is favoured for many official purposes and it can be applied, with very little sample preparation, to injections, tablets and solution-tablets. For ointments and similar preparations it is not directly applicable since high results may be obtained due to iodine absorption by the base. For preparations of this type Boymond has recommended iodimetric determination after mixture with benzene and extraction with water. 

Uses Base for preparing premuim quality, free rinsing, silicone defoamers Lanofoam Q-5 [Lenmar]... 

Uses Emulsifier, base for preparation of cutting oils, solv. degreasers, metal cleaners forms stable lubricants... 

Uses Base for preparation of low irritation and biodeg, shampoos and dishwashing detergents... 

J. Ladebeck and K. Kochloefl, in G. Poncelet et al., (editors). Scientific Bases for Preparation of Heterogeneous Catalysts. Elsevier Science B. V., Amsterdam. 1995. p. 1079. 

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