O-hydroxy benzoic acid

Phenols, unlike amines, cannot be acetylated satisfactorily in aqueous solution acetylation proceeds readily with acetic anhydride in the presence of a little concentrated sulphuric acid as catalyst. Salicylic acid (o-hydroxy-benzoic acid) upon acetylation yields acetylsalicylic acid or aspirin ... 

The Kolbe-Schmitt reaction has been applied to the preparation of other o hydroxy benzoic acids Alkyl derivatives of phenol behave very much like phenol itself... 

Figure 2. Linear regression plot of root growth inhibition of tomato and radish seedlings by o and -hydroxyphenyl) acids. o-Hydroxycinnamic acid, (o-hydroxyphenyl) acetic acid ( ) melilotic acid, 2-(o-hydroxyphenyl) butanoic acid ( ) o-hydroxy-benzoic acid, ( -hydroxypheny 1 )acetic acid (0) -hydroxycinnamic acid, =hydroxybenzoic acid, 3-( -hydroxyphenyl) propanoic acid (X) o-coumaryl glucoside, water control (----) (1 ). ...

The para isomer cannol form such a bond because the —OH and —COf groups are too far apart. By stabilizing the product, the internal hydrogen bond is thought to make o-hydroxy-benzoic acid more acidic than p-hydroxybenzoic acid. 

SYNS ACIDO SALICIUCO (ITALIAN) o-HYDROXY-BENZOIC ACID 2-HYDROXYBENZOIC ACID KERALYT ORTHOHYDROXYBENZOIC ACID RETARDER W D SA SAX... 

Acetic anhydride is often used to prepare acetate esters from alcohols and AT-substituted acetamides from amines. For example, aspirin (acetyl-salicylic acid) is prepared commercially by the acetylation of o-hydroxy-benzoic acid (salicylic acid) with acetic anhydride. Acetaminophen, a drug used in over-the-counter analgesics such as Tylenol, is prepared by reaction of p-hydroxyaniline with acetic anhydride. Note that the more nucleophilic -NH2 group reacts, rather than the less nucleophilic -OH group. 

An easier method of production of p-anisic acid is methy-lation of p-hydroxy benzoic acid obtained as a co-product during manufacture of o-hydroxy benzoic acid (salicylic acid) via Kolbe reaction of phenol and CO2... 

The active substance most often used in pyrotechnic whistles is gallic acid (3, 4, 5 trihydroxybenzoic acid). The potassium salts of benzoic acid of 2, 4, dinitrophenol and of picric acid (2, 4, 6 trinitro-phenol) and the sodium salt of salicylic acid (o-hydroxy benzoic acid) are also effective. They are combined with potassium chlorate, perchlorate, or nitrate (Formulas 156—160). 

Benzylsalioylic Acid 4 -Hyd/roxydiphenyl-methane- -carboxylie acid, 5-benzyl-o-hydroxy-benzoic acid). 

Salicylic acid — o-Hydroxy-benzoic acid XOOH... 

CONVERSION OF ACID ANHYDRIDES INTO ESTERS Acetic anhydride is often used to prepare acetate esters from alcohols. For example, aspirin (acetyl-salicylic acid) is prepared commercially by the acetylation of o-hydroxy-benzoic acid (salicylic acid) with acetic anhydride. 

Benzoic acid, /(-chloro-Benzoic acid, m-hydroxy-Benzoic acid, o-hydroxy-Benzoic acid, p-hydroxy-Benzoic acid, mercapto-Benzoic acid, methoxy-Benzoic acid, methyl-Benzoic acid, o-, m-, and... 

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