Alkaline condensation

Reaction of one mole of acetaldehyde and excess phenol in the presence of a mineral acid catalyst gives l,l-bis(p-hydroxyphenyl)ethane [2081-08-5], acid catalysts, acetaldehyde, and three moles or less of phenol yield soluble resins. Hardenable resins are difficult to produce by alkaline condensation of acetaldehyde and phenol because the acetaldehyde tends to undergo aldol condensation and self-resinification (see Phenolic resins). 

Direct Orange 15 (Cl 40003) [1325-35-5] (13), which is made by reducing the alkaline condensation product equivalent to Direct YeUow 11 with sulfide or formaldehyde, is an important paper dye used in dyeing brown paper for bags. 

This controUed synthesis gives a purer product than alkaline condensation of 4-nitrotoluene-2-sulfonic acid alone and is the reason for its brightness (4). 

Cinnamaldehyde, [14371-10-9] CgH CH=CHCHO (bp, 253°C at 101.3 kPa), produced by the alkaline condensation of benzaldehyde and acetaldehyde is the main ingredient in cassia oil. It is used in soap perfumes and as an intermediate in the production of other flavor and fragrance compounds. 

The Pfitzinger reaction consisting in the alkaline condensation of isatin or 6-bromoisatin with ketones has been applied extensively by Buu-Hoi et af.211.279.310.316,525,553 Cagniant, to acetylthio-... 

Darzens claims a method in which a ketone is condensed with chloracetic-ether in the presence of an alkaline condensing agent. For example, acetone reacts with chloracetic-ether as follows —... 

Carrythrough of BW solids with the condensate. Highly alkaline condensate Pre-boiler metal damage pH control out of balance Fouling to DA vent, check valves and FW pump... 

Variable pH of returned condensate, which affects FW quality BW is always alkaline (often strongly caustic) and highly alkaline condensate may cause amphoteric corrosion to metal components in the condensate system... 

Atophan can also be obtained by alkaline condensation of isatin with acetophenone. (Formulate.)... 

Alkaline condensation of 4-isopropylbenzaldehyde and propanal results, via the aldol, in the formation of 2-methyl-3-(4-isopropylphenyl)-2-propenal. The unsaturated aldehyde is hydrogenated selectively to the saturated aldehyde in the presence of potassium acetate and a suitable catalyst, such as palladium alumina [150] ... 

On an industrial scale, cinnamaldehyde is prepared almost exclusively by alkaline condensation of benzaldehyde and acetaldehyde. Self-condensation of acetaldehyde can be avoided by using an excess of benzaldehyde and by slowly adding acetaldehyde [154]. 

Burrell (Ref 9) stated that technical DPE was manufd in the USA by Heyden Chem Corp, Garfield, New Jersey, by the alkaline condensation of formaldehyde and acetaldehyde, modifying the proportions and conditions of re-... 

Diphenyl-4,10-dicarboxy-6-methyl-l,7-phenanthroline (25) has been obtained179 along with the quinoline derivative (24) by the alkaline condensation of acetophenone with the substituted isatin (23). 

Alkaline condensation of dinitrostilbenedisulfonic acid with aminoazo compounds produces a number of highly fast substantive dyes with industrial importance, especially in the shades orange, scarlet, and brown [6], Example C. I. Direct Orange 39, 40215 [1325-54-8] (for synthesis, see Section 3.3.4). 

In the third approach (39, 40, 72) the quinolizidone ester was alternatively prepared. The Ullmann reaction of 6-bromoveratraldehyde with methyl 4-hydroxycinnamate afforded biphenyl ether aldehyde (164) in 55% yield. The alkaline condensation of 164 with pelletierine gave a mixture of stereo-isomeric quinolizidone acids (158 and 159). Esterification with dimethyl sulfate yielded a mixture of trans- and cis-fused quinolizidine esters (160 and 161) in a 13 1 ratio after separation on silica gel. 

D-Mannose. —In contrast to the arabinoses and D-erythrose, the alkaline condensation reaction mixture of D-mannose and nitromethane in methanol remains heterogeneous throughout. However, visual inspection shows a moderately rapid replacement of the crystalline sugar in the insoluble phase by the amorphous sodium ocz-nitroalcohols. Both epimeric nitroalcohols are obtained in the crystalline state in a combined yield of approximately 55 percent. The separation of 1-nitro-... 

Alkali siliconates are obtained by highly alkaline condensation of methyltrimethoxysilane with potassium hydroxide. In the field of masonry protection, potassium methyl siliconates of general formula CH3Si(0H)20 are used predominantly for factory impregnation of building materials, but hardly ever nowadays for fafade treatment [16,25,27]. 

There are several types of polyaryl sulfones available commercially. The classic polysulfone (Udal) was produced by the nucleophilic displacement of the chlorine substituents on bis(p-chlorophenyl) sulfone by the sodium salt of blsphenol A.Another polysulfone (Astrel) is produced by the Friedel-Crafts condensation of biphenyl with oxy-bis(benzene sulfonyl chloride). Another polysulfone (Vitrex), is produced by the alkaline condensation of bis(chlorophenyl) sulfone. (28.)Blends of polysulfones with ABS (Arylon, Mlndel) and SAN (Ucardel) are available. 

Cyclic products from the reaction of /)-substituted phenols with formaldehyde may be formed during the alkaline condensation reaction. These calix(4)arenes contain both methylene and dimethylene ether links and form even-numbered cycles ranging from k = 4 to = 8 (BCnop et al, 1989). 

RA Barkhau, EW Malcolm, DR Dimmel. Insoluble Lignin Models (5) Preparation and Alkaline Condensation Reactions of a Polymer-Bound Quinone Methide. J Wood Chem Technol 14 17, 1994. 

EC Craven. The alkaline condensation of acetone. J AppI Chem. 13 71-76, 1963. 

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