2- phenol sulphate, hydrolysis

The preparation of phenols by hydrolysis of benzediazonium ions is well known in the literature (ref. 10). It involves the preparation of a diazonium salt, e.g. the diazonium hydrogenosulfate by treatment of the aniline hydrogen sulphate with sodium nitrite in dilute aqueous sulphuric acid, followed by hydrolysis in more concentrated aqueous sulphuric acid. The temperature of the hydrolysis is maintained at the boiling point of the aqueous acid by proper adjustment of the concentration of the sulphuric acid and the phenol formed removed from the reaction medium by means of steam distillation in order to minimise the coupling of the formed phenol with the diazonium salt introduced. 

R3. Rao, K. S., Sastry, P. S., and Ganguly, J., Studies on metabolism of vitamin A. 2. Enzymic synthesis and hydrolysis of phenolic sulphates in vitamin-A-defident rats. Biochem. J. 87,312-317 (1963). 

First, acetamenaphthone (I) undergoes hydrolysis in acidic medium to yield the corresponding phenol and secondly, this phenol is oxidised quantitatively with ammonium ceric sulphate to give the resulting 1, 4-dione derivative (II). 

This reagent has proved especially important in the study of the constitution of the sugars, and of cellulose. A series of methyl-celluloses has been obtained, and by the study of their hydrolysis, or decomposition in a vacuum, some light has been thrown on the structure of the cellulose molecule. (J. S. C. I., 41, 362 R.) In the laboratory dimethyl sulphate is much employed in the methylation of phenols and naphthols. Diethyl sulphate is not so suitable for such alkylations as its lower homo-logue. 

Recently, a new and efficient synthesis of cyprodime from naltrexone (2) has been reported [73], Firstly, the tetrazolyl ether (27) was formed by reaction of naltrexone with 5-chloro-l-phenyl-1 Ff-tetrazole [74], Catalytic hydrogenation afforded 3-deoxynaltrexone (28) which was methylated with dimethyl sulphate to give the enol ether (29). Acid hydrolysis gave the known morphinanone (30) [75] which was treated with activated zinc and ammonium chloride to yield the phenol (31). 4-O-Methylation with phenyltri-methylammonium chloride afforded cyprodime (23, Scheme 3.4) [75],... 

The primary metabolite of benzene is phenol. Phenol is excreted as glucuronide and sulphate conjugates in urine. Total phenolic metabolites (phenol, phenyl sulfate, and phenyl glucuronide) have been determined by hydrolyzing urine samples either enzymatically or by acid, then extracting the phenol with solvent. Phenol is then measured by GC or HPLC techniques. Enzymatic hydrolysis coupled with GC/FID has been reported the detection limit is 1 mg/L and recovery is excellent (92-98%) (Buchet 1988). Acid hydrolysis followed by HPLC provides quantitative recovery ( 100%) and a detection limit of 0.01 nmol/g (Murray and Adams 1988). Sulfate and glucuronide conjugates... 

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