Pentetrazol

Manufacturing Process

A solution of 9.8 g cyclohexanone and 8.6 g HNO3 in about 250 ml benzene were slowly added dropwise to 20 ml concentrate sulfuric acid in 100 ml benzene by ice cooling and stirring. After ending of a generation of N2 (0.1 moles) to a corresponding quantity of cyclohexane (0.1 moles). Acid layer was diluted with ice, and made neutral with strong alkaline to give a reaction product as oil. Then it was exrtacted with chloroform, all solvents were distilled and the residue was diluted with water. The desired 6,7,8,9tetrahydro-5H-tetrazoloazepine dropped. Yield was 7.5 g after recrystallization from ester or distillation. M.P: 65°C.

Therapeutic Function

Analeptic, Central stimulant

Air & Water Reactions

Dust can be explosive when suspended in air at specific concentrations. Water soluble.

Reactivity Profile

Pentetrazol is incompatible with oxidizing agents. . Azo, diazo, azido compounds can detonate. This applies in particular to organic azides that have been sensitized by the addition of metal salts or strong acids. Toxic gases are formed by mixing materials of this class with acids, aldehydes, amides, carbamates, cyanides, inorganic fluorides, halogenated organics, isocyanates, ketones, metals, nitrides, peroxides, phenols, epoxides, acyl halides, and strong oxidizing or reducing agents. Flammable gases are formed by mixing materials in this group with alkali metals. Explosive combination can occur with strong oxidizing agents, metal salts, peroxides, and sulfides. Azo dyes can be explosive when suspended in air at specific concentrations.

Fire Hazard

Flash point data for Pentetrazol are not available. Pentetrazol is probably combustible.

Biological Activity

CNS stimulant that induces kindling in vivo . Causes alterations in excitatory and inhibitory neurotransmitter systems.

Biochem/physiol Actions

Pentylenetetrazole is a non-specific central nervous system (CNS) stimulant and convulsant. PTZ induces oxidative stress and increases cortical malondialdehyde content and affects hippocampus, resulting in seizures.

Safety Profile

A human poison by ingestion and intravenous routes. Poison experimentally by ingestion, intravenous, intraperitoneal, subcutaneous, rectal, and parenteral routes. When heated to decomposition it emits toxic fumes of NOx.

Purification Methods

pKEst Crystallise metrazol from diethyl ether and dry it under vacuum over P2O5, or distil it. [Schmidt Chem Ber 57 704 1924, Beilstein 26 II 213.]

Definition

ChEBI: An organic heterobicyclic compound that is 1H-tetrazole in which the hydrogens at positions 1 and 5 are replaced by a pentane-1,5-diyl group. A central and respiratory stimulant, it was formerly used for the treatment of cough and other espiratory tract disorders, cardiovascular disorders including hypotension, and pruritis.

Brand name

Cardiazol (Knoll).

General Description

White crystalline powder or granular solid with a slightly pungent odor. Bitter taste. Aqueous solutions neutral to litmus.