Hippuric Acid → Azlactone

HRID 359608

Reaction equation

HRID 359608 reaction equation
[C:1]([OH:13])(=[O:12])[CH2:2][NH:3][C:4]([C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1)=O.C(OC(=O)C)(=O)C>>[C:6]1([C:4]2[O:13][C:1](=[O:12])[CH2:2][N:3]=2)[CH:7]=[CH:8][CH:9]=[CH:10][CH:11]=1

Participants

3

Conditions

Temperature
80 °C

Procedure

101.6 g (0.567 mol) of hippuric acid was dispersed in 330 ml (3.49 mol) of acetic anhydride and heated to 80° C. in a water bath for about 20 minutes, thereby obtaining a solution of 2-phenyl-2-oxazolin-5-one. The thus obtained solution was cooled to -20° C. in a dry ice acetone bath. Thereto 93 g of anhydrous sodium acetate was added and the diaszonium salt solution prepared in advance was added to the mixture with vigorous stirring at a rate so as to maintain the reaction temperature at not higher than -10° C. After the completion of the dropping, the reaction mixture was held at -10° C. for 2 hours, and thereafter was stirred for 5 hours in an ice bath. Further, the mixture was stirred for one night in a water bath, and thereafter 1.5 l of water was added to filter out a yellow precipitate, which was washed with water to obtain the objective product.

Sources & evidence

ORD record
ord-4291b06ca06a4d55be58c11fa2be0793
Source dataset
uspto-grants-1991_03
Patent number
US05001275

Linked notes

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