[4] As the brand name Theratuss, it was approved by the FDA in 1962, on evidence of safety only.

It was withdrawn from the US market in 1972 when the manufacturer, Bristol Myers Squibb, failed to produce evidence of efficacy.

[5] Clinical studies showed that it did not decrease cough frequency at recommended dosages.

[6] Infrequent side effects include nausea, vomiting, drowsiness, fatigue, rash, tachycardia and seizures.

The reaction of this reactive intermediate with 2-[2-(piperidyl)ethoxy]ethanol [3603-43-8] (3) gives the ester, thus completing the synthesis of Pipazethate (4).