Cresols, carbonylation

For example, nylon 66 will dissolve in formic acid, glacial acetic acid, phenol and cresol, four solvents which not only have similar solubility parameters but also are capable of acting as proton donors whilst the carbonyl groups on the nylon act as proton acceptors (Figure 5.6). 

Acid catalyzed Sehiff base condensation of 2,6-diformyl-p-cresol and TETA (triethylenetetraamine) with Pr3+ as the template cation (in methanol) afforded a 1 1 product containing a tetraclinching alcohol (Eq. 9b, Table 9) [132]. One of the carbonyl groups was acetylated under mild acidic conditions. The 10-coord-ination around Pr3 + achieved by one aryloxide site, one imine and three amino nitrogen, two bidentate nitrate anions and one molecule of methanol is best described as a bicapped square antiprism. 

In contrast to the above, Figure 21 shows that the antioxidant did not inhibit the rate of either discoloration or carbonyl formation under mercury-arc exposure. Grassie and Weir (5) also reported that under 2537-A. irradiation the antioxidant, 2,6-di-tert-butyl-p-cresol, had no effect on the rate of polystyrene photooxidation. It may be concluded,... 

Chen C-L, Connors WJ (1974) New carbonyl compounds from the alkaline ferncyamde dehydrogenation of p cresol J Org Chem 39 3877-3880 Chum HL, Johnson DK, Ratcliff M, Black S, Schroeder HA, Wallace K (1985) Comparison between lignins produced by steam explosion and organosolv pretreatments Proc 1985 Int Symp Wood Pulp Chem, Vancouver, BC, Canada, August 26-30, 1985, Tech Pap 223-226... 

Chen C-L, Connors WJ (1974) New carbonyl compounds from the alkaline ferricyanide dehydrogenation of p-cresol. J Org Chem 39 3877-3880... 

In the laboratory of V. Singh a novel and efficient stereospecific synthesis of the marine natural product capnellene from p-cresol was developed. After rapidly assembling the desired carbon framework, it was necessary to remove the carbonyl group from the tricyclic intermediate which was accomplished using Barton s deoxygenation procedure. 

Cresol-formaldehyde, phenol-formaldehyde, and chlorinated cresol-formaldehyde novolac resins all undergo photo-oxidation upon UV-irradiation in air. The change of the carbon core level signals is shown in Fig. 8. The new IR band at about 1720 cm-, corresponding to formation of a carbonyl group, is also found after photo-oxidation of novolac resin. These oxidized layers of the novolac film are limited to a very shallow superficial surface only about 500 A thick, even after long deep UV irradiation, as discussed below in reference to photostabilization of resist images. 

HIDROXILAMINA (Spanish) (7803-49-8) A powerful reducing agent. Aqueous solution is a base. Contact with water or steam causes decomposition to ammonium hydroxide, nitrogen, and hydrogen. Contaminants and/or elevated temperatures above (reported at 158°F/70°C and 265°F/129°C) can cause explosive decomposition. Moisture in air or carbon dioxide may cause decomposition. Violent reaction with oxidizers, strong acids, copper(II) sulfate, chromium trioxide, potassium dichromate, phosphorus chlorides, metals calcium, sodium, zinc. Incompatible with carbonyls, pyridine. Forms heat-sensitive explosive mixtures with calcium, zinc powder, and possibly other finely divided metals. Aqueous solution incompatible with organic anhydrides, acrylates, alcohols, aldehydes, alkylene oxides, substituted allyls, carbonyls, cellulose nitrate, cresols, caprolactam solution, epichlorohydrin, ethylene dichloride, glycols, isocyanates, ketones, nitrates, phenols, pyridine, vinyl acetate. Attacks aluminum, copper, tin, and zinc. 

This method has been extensively exploited for the synthesis of a large group of 3H-2,1-benzoxathiole 1,1-dioxide derivatives known as sulphonephthaleins, many of which, such as phenol red, p-cresol red and bromothymol blue are well known acid-base indicators. There is excellent coverage of this subject in Breslow and Skolnik s monograph8 and equation 60 merely serves to illustrate two representative syntheses81,82. The sulphonephthaleins can also be prepared from 3ff-2,l-benzoxathiole-l-dioxide derivatives with reactive substituents (such as dichloro or carbonyl) at the 3-position (see Section III.D.3). 

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