Benzalacetone

Chemical properties

Yellow Solid

Chemical properties

4-Phenyl-3-buten-2-one has a sweet, floral, creamy, pungent odor reminiscent of coumarin and rhubarb with a sweet, pungent flavor. It is not very stable.

Occurrence

Occasionally Benzalacetone is used in perfumery for Sweet Pea (used to be a “must” in this type of fragrance), in Appleblossom, etc., often in combination with Neroli and Hyacinth bases. Also used in flavors, particularly in Chocolate, Cocoa, Cherry, Fruit, Nut, Vanilla, etc. - but usually at very low concentration. Concentration in finished product will rarely exceed 0.2 to 0.5 ppm.

The Uses of Benzalacetone

brightener in acid zinc electroplating,also used as an organic synthesis intermediate in flavor and fragrance, pharmaceutical industries

The Uses of Benzalacetone

In perfumery, organic syntheses.

The Uses of Benzalacetone

Benzylideneacetone is used chiefly as a scent in the manufacture of perfume, drugs & electroplating.

Definition

ChEBI: Trans-benzylideneacetone is the trans-isomer of benzylideneacetone. It acts as an inhibitor of the enzyme phospholipase A2 (EC 3.1.1.4) of insects like diamond back moth. It has a role as a flavouring agent, a fragrance, a bacterial metabolite and an EC 3.1.1.4 (phospholipase A2) inhibitor.

Preparation

By condensing benzaldehyde and acetone in the presence of an alkaline condensing agent.

Aroma threshold values

Aroma characteristics at 1.0%: sweet, fruity and jamy cherry-like, aldehydic cinnamon spicy, herbal, anisic, balsamic, toasted almond nutty and woody with slight powdery vanilla nuances.

Taste threshold values

Taste characteristics at 5 to 10 ppm: aldehydic, coumarinic and balsamic, slightly nutty, floral and fruity with woody nuances.

Synthesis Reference(s)

The Journal of Organic Chemistry, 58, p. 5595, 1993 DOI: 10.1021/jo00073a011
Tetrahedron Letters, 28, p. 913, 1987 DOI: 10.1016/S0040-4039(00)95872-6

General Description

trans- 4-Phenyl-3-buten-2-one is substrate for glutathione transferase. It reacts with methyl- and benzylguanidine to yield aromatic N²-substituted 2-pyrimidinamines.

Biochem/physiol Actions

Taste at 5-10 ppm

Safety Profile

Poison by intravenous route. Moderately toxic by intraperitoneal route. A skin irritant. A flammable liquid. When heated to decomposition it emits acrid smoke and irritating fumes. See also KETONES.

Purification Methods

Crystallise it from pet ether (b 40-60o), or distil it (b 137-142o /16mm). [Beilstein 7 IV 1003.]