У нас вы можете посмотреть бесплатно Making Phenyl Propiolic acid или скачать в максимальном доступном качестве, видео которое было загружено на ютуб. Для загрузки выберите вариант из формы ниже:
Если кнопки скачивания не
загрузились
НАЖМИТЕ ЗДЕСЬ или обновите страницу
Если возникают проблемы со скачиванием видео, пожалуйста напишите в поддержку по адресу внизу
страницы.
Спасибо за использование сервиса ClipSaver.ru
This video takes you on a fascinating journey into the world of organic chemistry as we synthesize phenyl propiolic acid, a versatile building block with applications in pharmaceuticals, dyes, and materials science. We'll start with cinnamic acid, a naturally occurring compound found in cinnamon, and guide you through the multi-step process of converting it into this valuable alkyne. This two-step process, starting with bromination and followed by a double elimination, is a well-established route in organic chemistry. Step 1: Bromination of Cinnamic Acid The first step involves the electrophilic addition of bromine (Br_2) to the double bond of cinnamic acid. This reaction typically proceeds with anti-addition through a cyclic bromonium ion intermediate. Because the cinnamic acid starting material is usually in its trans configuration, the anti-addition of bromine results in the formation of a specific stereoisomer: 2,3-dibromo-3-phenylpropanoic acid. The reaction is usually carried out in a solvent like glacial acetic acid or dichloromethane. You can monitor the progress by the disappearance of the reddish-brown color of bromine. Step 2: Elimination with Alcoholic KOH The second step is a double elimination reaction to form the alkyne. This is achieved by reacting the 2,3-dibromo-3-phenylpropanoic acid with a strong base, such as alcoholic potassium hydroxide (KOH). The presence of a high concentration of a strong base in an alcohol solvent favors E2 elimination over substitution reactions. The base deprotonates the carboxylic acid group and then initiates two successive eliminations. First, one molecule of HBr is eliminated, forming an intermediate bromo-alkene. A second molecule of HBr is then eliminated, generating the desired triple bond and yielding phenyl propiolic acid. This step is often performed with heating to drive the reaction to completion. What You'll Learn Stereochemistry of Addition Reactions: You will observe the importance of stereochemistry as you add bromine in an anti-fashion to the trans double bond. Elimination Reactions (E2): This synthesis is an excellent practical example of an E2 reaction and how reaction conditions (strong base, alcohol solvent, heat) can be used to favor elimination. Purification and Characterization: After the reaction, you'll need to acidify the solution to precipitate the phenyl propiolic acid. You can then purify your product through recrystallization and confirm its identity and purity using techniques like melting point analysis. This method offers a hands-on experience with fundamental organic reaction mechanisms, providing a clear and direct path to a valuable chemical compound. support me through Paypal →https://www.paypal.me/akhilthechemist