Циклопентилтрифенилфосфония бромид

Description

Cyclopentyltriphenylphosphonium bromide is a phosphonium salt, a Wittig reagent for introducing a cyclopentylidene group into the target molecule. When treated with a base, it produces a ylide that reacts with aldehydes and ketones in a Wittig reaction to form an alkene, where a new double bond is formed strictly between the carbonyl carbon atom and the ylide carbon atom—the regiospecificity of the reaction makes the position of the double bond predictable, unlike many other olefination methods. The reagent is used for cyclopentylidene olefination in the synthesis of active substances, in particular in schemes for the production of pharmaceutical substances, where the reaction gives the target product with a yield of about 81%. The use of salt as a source of halide ion in the mechanochemical synthesis (ball mills) of anion-coordinated supramolecular structures is also described - this solvent-free approach reduces the volume of synthesis waste. Three phenyl substituents on the phosphorus atom ensure the stability of the salt against oxidation and the convenience of its isolation in crystalline form, which is typical for phosphonium salts of the triphenylphosphine class in general.

Basic Attributes

• CAS No.: 7333-52-0
• Chemical formula: C23H24P Br
• Molecular weight: 411.31
• Exact weight: 410.08000
• BRN: 3580193
• DSSTox ID: DTXSID80371008
• PSA Features: 0
• XLogP3: 1.92710

Physico-chemical characteristics

• Melting point: 261-263 °C

Scope of application

The main purpose is the Wittig reagent for the cyclopentylidene olefination of carbonyl compounds in fine organic synthesis, including the production of pharmaceutical intermediates. An additional area is the source of bromide ion in mechanochemical (solvent-free) syntheses of anion-coordinated architectures by the ball mill method. The Wittig reaction as a whole remains one of the most reliable methods for producing alkenes of a given structure in laboratory and industrial practice precisely because of the predictability of the position of the new double bond, and the replacement of the ylide with a cyclopentylidene fragment expands the available set of carbocyclic olefins.

Safety Information

• Hazard class code: 36/37/38
• Safety instructions: 26-36/37/39
• Tags: Xi (annoying)
• Hazard Note: Irritant

Storage and transportation conditions

A solid crystalline substance with a melting point of 261-263 °C, store in a tightly closed container, in a dry place, away from sources of moisture, since phosphonium salts are able to gradually absorb air moisture. When working, use gloves and safety glasses - the substance is irritating to the skin, eyes and respiratory tract (code 36/37/38). Special UN transport codes and hazard categories for the position are not indicated in the passport, which is typical for solid organic phosphonium salts of low hazard class.