With KOH

It is a valuable dyestuffs intermediate. When fused with KOH, two molecules of benz-anthrone combine at the positions marked above to give a dibenzanthrone which is in itself a vat dye. Also used as an intermediate for the preparation of the valuable Caledon Jade Green. 

Synthesis No control is need because only the ketoacid can enolise and the aldehyde is more electrophilic. TM 89 is formed in 80% yield when the two starting materials are mixed in MeOH with KOH at room temperature tHelv. Chim. Acta. 1931,14, 783). 

Appamtus 2-1 two-necked, round-bottomed flask, provided with a stopper and a 40-cm Vigreux column. This column was connected to a descending condenser and a receiver, fl tube filled with KOH pellets was placed betv/een the water pump and the receiver. 

We presume that the dilithiopropyne causes partial isomerization into the allenic derivative. The treatment with KOH is to complete this transformation. When the latter treatment was not carried out, considerable amounts of the acetylenic diacids were sometimes found in the crude product. 

Bote 2. If this treatment with KOH is omitted, the product may contain considerable amounts of H00C-CH(CH3)CzC-C00H. 

Apparatus 1-1 three-necked flask, provided with an evacuatable dropping funnel, a gas-tight mechanical stirrer and a 45-cm Vigreuxcolumn. The column was connected to a condenser and a single receiver, cooled at -75°C. Between the receiver and the water pump was placed a tube filled with KOH pellets. 

To a mixture of O.BB mol of anhydrous lithium chloride and 100 ml of OMSO was added a solution of 0.40 mol of the acetylenic tosylate (for a general procedure concerning the preparation of acetylenic tosylates, see Chapter VllI-3, Exp. 3) in IBO ml of DMSO. The flask was equipped for vacuum distillation (see Fig. 5). Between the receiver, which was cooled at -75°C, and the water-pump was placed a tube filled with KOH pellets. The apparatus was evacuated (10-20 mmHg) and the flask gradually heated until DMSO began to reflux in the column. The contents of... 

Acetylene is also protected as propargyl alcohol (300)[2H], which is depro-tected by hydrolysis with a base, or oxidation with MnOi and alkaline hydrolysis. Sometimes, propargyl alcohols are isomerized to enals. Propargyl alcohol (300) reacts with 3-chloropyridazine (301) and EtiNH to give 3-diethylami-noindolizine (303) in one step via the enal 302[2I2]. Similarly, propargyl alcohol reacts with 2-halopyridines and secondary amines. 2-Methyl-3-butyn-2-ol (304) is another masked acetylene, and is unmasked by treatment with KOH or NaOH in butanol[205,206,213-2l5] or in situ with a phase-transfer cata-lyst[2l6]. 

Aqueous caprolactam is polymerized alone and in the presence of sebacic acid (S) or hexamethylenediamine (H).t After a 24-hr reaction time, the polymer is isolated and the end groups are analyzed by titrating the carboxyl groups with KOH in benzyl alcohol and the amino groups with p-toluenesulfonic acid in trifluoroethanol. The number of milliequivalents of carboxyl group per mole caprolactam converted to polymer, [A ], and the number of milliequivalents of amino groups per mole caprolactam converted to polymer, [B ], are given below for three different runs ... 

Compounds of iron(V) are extremely rare. K FeO has been prepared by heating K FeO with KOH in oxygen at 700—800°C. It appears to contain tetrahedral [FeOJ anions. An impure sodium salt has also been prepared. 

Manganate(VI) formed in the initial oxidation process must first be dissolved in a dilute solution of potassium hydroxide. The concentrations depend on the type of electrolytic cell employed. For example, the continuous Cams cell uses 120 150 g/L KOH and 50 60 g/L K MnO the batch-operated Bitterfeld cell starts out with KOH concentrations of 150 160 g/L KOH and 200 220 g/L K MnO. These concentration parameters minimize the disproportionation of the K MnO and control the solubiUty of the KMnO formed in the course of electrolysis. 

Other Tripolyphosphates. Potassium tripolyphosphate [24315-83-1] (KTP), K P O q, has a high aqueous solubihty (near 180 g/100 g) and has been used in place of STP for Hquid detergents. The potassium salt, however, is more expensive than STP. Sodium potassium tripolyphosphate (SKTP), Na K P O Q, is prepared by calcination of a feed Hquor having the proper Na20/K20ratio or by reaction of sodium trimetaphosphate with KOH. For some detergent or food appHcations, SKTP may provide the optimum compromise between solubihty and cost. 

Miniature zinc—mercuric oxide batteries may be made with either KOH or NaOH as the electrolyte. Cells having KOH operate more efficiently than those having NaOH at high current drains (Eig. 12) because of the higher conductivity of KOH. On the other hand, batteries with KOH are more difficult to seal, cells with NaOH are more resistant to leakage. 

The treatment of 4-benzoyl-3-phenylisoxazolin-5-one with KOH generated 3,5-diphenyl-isoxazole-3-carboxylic acid via a ring-opened intermediate as shown in Scheme 69 (61CB1956). 

Mild base does not effect isoxazolidine ring cleavage by fission of the N—O bond rather, C—O bond cleavage takes place <77AHC(2l)207). The reaction of iV-trimethyl-silylisoxazolidine (185) with KOH produced a /3-hydroxyketone oxime (Scheme 59) (74DOK109). 

SPh boron detenuination in form of complex with Azomethine-H is the reliable microanalytical method for boronorganic compounds, carboranes, metallacarboranes, etc. Before boron determination the samples should be melted with KOH at 900°C. 

Janovsky comptex (4). m-OIntrobenzene 3 (1 00 g, 6 mmol) In acetone (10 mL) was Shaken vigorously with KOH pellets for 15 mm The purple mixture was filtered, the KOH pellets washed with acetone arxl to the combined solutions was added benzene (20 mL) The black-violet precipitate was recrystalHzed Irom benzene-acetone to give 135 mg of 4 (10%), mp 250 C. 

Aniline [62-53-3] M 93.1, f -6.0", b 68.3/lOmm, 184.4"/760mm, d 1.0220, n 1.585, n s 1.5832, pK 4.60. Aniline is hygroscopic. It can be dried with KOH or CaH2, and distd at reduced pressure. Treatment with stannous chloride removes sulfur-containing impurities, reducing the tendency to become coloured by aerial oxidn. Can be crystd from Et20 at low temps. More extensive purifications involve preparation of derivatives, such as the double salt of aniline hydrochloride and cuprous chloride or zinc chloride, or A -acetylaniline (m 114") which can be recrystd from water. 

Non-basic materials, including nitro compounds were removed from aniline in 40% H2SO4 by passing steam through the soln for Ih. Pellets of KOH were added to liberate the aniline which was steam distd, dried with KOH, distd twice from zinc dust at 20mm, dried with freshly prepared BaO, and finally distd from BaO in an allglass apparatus [Few and Smith J Chem Soc 753 7949]. Aniline is absorbed by skin and is TOXIC... 

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