Identify a medicinal compound having amide linkage.

Which of the following is a chlorine-containing artificial sweetener?

An artificial sweetener $X$ is a halogen-containing compound and artificial sweetener $Y$ is a sulphur-containing compound. $X$ and $Y$ respectively are:

Barbiturates are hypnotic agents. Veronal is a derivative of barbituric acid. It can be synthesized by the following sequence,then the structure of veronal $(P)$ is :
$CH_2(CO_2Et)_2$ $\xrightarrow[EtI]{EtO^-}$ $\xrightarrow[EtI]{EtO^-}$ $\xrightarrow{Urea}$ $(P)$

Which of the following compounds is not an antacid?

Examples of antihistamine $(X)$ and cationic detergent $(Y)$ are