C6H5CONH2

Benzamide, also known as benzenecarboxamide, is an aromatic carboxamide with the chemical formula C7H7NO (molar mass about 121.14 g/mol). It is the amide derived from benzoic acid by replacement of the hydroxyl group with an amino group (CONH2). The common name and the systematic name describe the same compound.

Structure and properties. Benzamide consists of a benzene ring attached to a carbonyl amide group (CONH2). The amide linkage enables hydrogen bonding, giving rise to a solid at room temperature with a relatively high melting point. It is a colorless to white crystalline substance that is sparingly soluble in water but dissolves in a range of organic solvents such as ethanol, acetone, and chloroform. Infrared spectroscopy shows the characteristic amide carbonyl band around 1650 cm−1 and N–H stretches in the 3200–3400 cm−1 region.

Preparation. Benzamide is typically prepared by hydrolysis of benzonitrile (C6H5CN) under acidic or basic conditions, which converts the nitrile into the amide. It can also be formed through amide formation from benzoic acid derivatives using ammonia and dehydrating reagents, though these routes are less common on a laboratory scale.

Uses. It serves as an intermediate in the synthesis of various pharmaceuticals, dyes, and agrochemicals. It is sometimes used as a reference compound in analytical laboratories and as a starting material for the preparation of substituted benzamides.

Safety. Benzamide presents low to moderate irritation potential and should be handled with standard laboratory safety practices to avoid ingestion, inhalation, or contact with skin and eyes. It should be stored away from strong oxidizers.