Identification of an impurity in diuretic paraflutizide and its detection in the dosage form was written by Blaschke, Gottfried;Maibaum, Juergen. And the article was included in Pharmazeutische Zeitung in 1985.Electric Literature of C10H11FO2 This article mentions the following:
During experiments in the chromatog. separation of enantiomers, a considerable amount of an impurity was detected in paraflutizide (I) [1580-83-2]. This impurity, also detectable by TLC, was identified by spectroscopic methods as 6-chloro-3-(2-fluorobenzyl)-3,4-dihydro-2H-1,2,4-benzothiadiazine-7-sulfonamide-1,1-dioxide (II) [96782-83-1]. An unambiguous synthesis confirmed this structure. 19F-NMR spectroscopy enabled the fast and reliable identification of II in a I-containing dosage form besides a large excess of other ingredients. In the experiment, the researchers used many compounds, for example, Ethyl 2-fluorophenylacetate (cas: 584-74-7Electric Literature of C10H11FO2).
Ethyl 2-fluorophenylacetate (cas: 584-74-7) belongs to esters. Esters are widespread in nature and are widely used in industry. In nature, fats are in general triesters derived from glycerol and fatty acids. Esters are responsible for the aroma of many fruits. Esters contain a carbonyl center, which gives rise to 120° C–C–O and O–C–O angles. Unlike amides, esters are structurally flexible functional groups because rotation about the C–O–C bonds has a low barrier. Their flexibility and low polarity is manifested in their physical properties; they tend to be less rigid (lower melting point) and more volatile (lower boiling point) than the corresponding amides. Electric Literature of C10H11FO2
Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics