General procedure method B

To a solution of the aldehyde (1.5 mmol) in anhydrous THF (2 ml) at -60°C is added dropwise a solution of lithium bis(trimethylsilyl)amide. The resulting solution is warmed to —30°C (20 min), and then a solution of the anion of tosylmethylisocyanide (1.4 mmol) is added. After stirring (30 min) at —78°C, the solution is allowed to warm up to 0°C (2 h), then stirred at room temperature (16h). The reaction mixture is then worked up as above (method A). 

A solution of lV-(substituted benzylidene)methylamine A(-oxide (18) (0.01 mol) in a mixture of ethanol (50 ml) and water (20 ml) is shaken with KCN 

5-diphenyl-l-propyl- (12%), 2,4-diphenyl-1,5-dipropyl- (25%) and 4-butyl-5-phcnyl-l-propylimidazoles (3%) [31]. This approach suffers from the twin problems that both the azirines and imines must be prepared before the cyclization is attempted, and there is no guarantee that good yields will be obtained (see also Chapter 6). 

Using a process similar to other 2-azaallenyl cyclizations, a number of novel histamine analogues have been made by applying the ring-chain transfer concept to the reaction of semicyclic 2-aza-3-methylthio-3-propeniminium iodides with methylamines possessing an acidic CH group [34 j. 

To a stirred suspension of potassium hydride (0.55 g, 1.38 mmol) in freshly distilled diglyme (2.0 ml), diethoxyacetonitrile [35] (0.129g, 1.0 mmol) and methyl isocyanoacetatc [36] (0.099 g, 1.0 mmol) in diglyme (1.5 ml) are added slowly with ice cooling under an argon atmosphere. The solution is heated at 70-80°C (5h), then cooled, quenched with saturated aqueous ammonium chloride, and extracted with dichloromethane (3 x 10ml) and ethyl acetate 

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ISO 2781 also details a procedure (method B) for use when it is necessary to cut the sample into small pieces to avoid trapped air. as might happen with narrow bore tubing. The test piece comprises a number of small smooth pieces within the size 4mm X 4mm x 6mm. These are weighed in a density bottle both with and without the remaining space filled with water. The bottle is also weighed without rubber both empty and filled with water. This is a more tedious procedure than method A and is generally only used as a last resort. Even with the test piece cut up, trapped air can still be a problem. 

For processes that generate particles (dust, mists, fumes, etc.) there is no general procedure to calculate the contaminant s velocity and flow rate. Data and figures exist for some processes de.scribing the contaminant generation process however, for dust-generating processes Method B or C is often used. 

Method A. 155- 160°C, 31 -SAalm h62 Method B see general procedure below... 

For formulations A and B, one general procedure is to solve the laminar flow equations which are linear and use the solution as the initial guesses for the nonlinear equations. Variations of this procedure have been used by Bending and Hutchison (B5), Wood and Charles (Wll), and Jeppson and Tavallaee (J2) in conjunction with the linearization method. 

The method described for the preparation of N-methyl-2-pyrrolidinethione is very similar to that of Peak and Stansfield 2 for the preparation of 4-thioacetylmorpholine. N-Methyl-2-pyrrolidinethione has also been prepared by the reaction of 2-chloro-N-methyl-A1-pyrrolinium chloride with hydrogen sulfide [yield 83% b.p. 144-145° (15 mm.)]3 and by heating N-methyl-2-pyrrolidinone with 2 equivalents of phosphorus pentasulfide in xylene [yield not reported b.p. 125-132° (10 mm.)].4 General procedures for the preparation of N,N-disubstituted thioamides have been reviewed.5, 6... 

Method B (general procedure). To a solution of NaHTe (5 mmol) prepared as described previously the carbonyl compounds (2 mmol) and the amine (2 mmol) are added at -20°C. The mixture is stirred for 20 h at room temperature. The precipitated black Te is filtered and the filtrate evaporated under vacuum. The residue is dissolved in EtOAc (20 mL) and acidified with dilute HCl. The combined aqueous layers are made basic with NaOH and extracted with EtOAc (2x30 mL). The extract is dried (Na2S04), concentrated and purified by TLC (elution with hexane/EtOAc). 

Method B (general procedure). Finely powdered Te (0.128 g, 1.0 mmol) is treated with an EtOH solution of sodium diethyl phosphite (1.5 mmol) in an apparatus which has been previously evacuated and flushed with argon. After a clear solution has formed, the a-haloketone (1.0 mmol) in dry EtOH or THE (2.0 mL) is injected. The mixture is stirred (25 or 80°C, 1-15 h) and then filtered through Celite with the aid of ether. The orange filtrate is evaporated at room temperature under vacuum (water pump) and the residue applied to an Si02 column, proceeding to elution (hexane/EtOAc) only after 30 min, to... 

Method B (general procedure)7 To an NaHTe solution, prepared from tellurium powder (1.27 g, 10 mmol) and NaBH4 (0.9 g, 24 mmol) in absolute EtOH (25 mL), is added the 2-haloethyl ester (10 mmol) in EtOH (5 mL). (The reaction takes place instantaneously for 2-bromoethyl esters at room temperature.) The mixture is stirred for 1 h, then acidified with dilute HCl, extracted with ether and the organic phase dried and evaporated. The residue is recrystalUzed from appropriate solvents to give pure carboxylic acids. 

Harborne, J.B., General procedures and measurement of total phenolics, in Methods in Plant Biochemistry, Vol. 1, Plant Phenolics, Harborne, J.B., Ed., Academic Press, London, 1989, chap. 1. 

Alkylation of Sulfonamides under Phase-Transfer Conditions (Method B) General Procedure 91 ... 

Fmoc-Protected /V"-(o)-Protected functionalized alkyl) Amino Acids 32 by Method B General Procedure 125 ... 

General Procedure for the a-Hydroxyalkylation of THF with Aldehydes using Triethyl-borane (1.0 m in THF) and TBHP (Method B) [12]... 

Another total synthesis of michellamines A-C, korupensamines A-D, and ancistrobrevine B has been developed by Hoye et al. [32], who emphasized that Suzuki coupling of the boronic acid derived from the naphthalene moiety with a THIQ-iodide proved to be the most generally effective method for forming the hindered biaryl bond. A racemic isochromane analogue of michellamines has been synthesized by a similar procedure [33]. 

Puig, 0., Caspary, F., Rigaut, G., Rutz, B., Bouveret, E., Bragado-Nilsson, E., Wilm, M. and Seraphin, B. (2001) The tandem affinity purification (TAP) method a general procedure of protein complex purification. Methods 24, 218-229. 

B) ( Barbier procedure ) a solution of LDA was slowly added to a solution of both reacting components in THF at - 78 °C. In general, the methods were equivalent. However, in some cases the side reactions could be minimized by using the method B. 

Quinazoline-4(3//)-thiones 13 are prepared in a very simple, one-step synthesis by treatment of 2-[(ethoxymethylene)amino] derivatives 12 with alcoholic sodium hydrosulfide. Numerous other hetero-fused pyrimidinethiones are also available by this procedure (Method Cyclization proceeds uniformly in very high yields, generally in excess of 90%. In some cases, since isolation and purification of (ethoxymethylene)amino derivatives results in the lowering of the overall yield, the one-step procedure, consisting of treatment of a 2-aminonitrile 11, either with a 1 1 mixture of triethyl orthofoimate and acetic anhydride or with triethyl orthoformate alone, to give an intermediate ethoxymethyleneamino derivative which, without isolation, is treated with an ethanolic solution of sodium hydrosulfide, is preferred for preparative purposes (Method B). In a few cases, conversion of the 2-aminonitrile to a 2-aminothioamide followed by cyclization with triethyl orthoformate (see p 47) competes favorably with the above procedure. 

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