Grignard Reagent: Formation, Synthesis & Preparation

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: History of the Grignard Reaction

You're on a roll. Keep up the good work!

Take Quiz Watch Next Lesson
Your next lesson will play in 10 seconds
  • 0:03 What Is a Grignard Reagent?
  • 1:09 Making a Grignard Reagent
  • 2:46 Synthesis
  • 3:40 Preparation
  • 4:55 Lesson Summary
Save Save Save

Want to watch this again later?

Log in or sign up to add this lesson to a Custom Course.

Log in or Sign up

Speed Speed

Recommended Lessons and Courses for You

Lesson Transcript
Instructor: Danielle Reid

Danielle has taught middle school science and has a doctorate degree in Environmental Health

What happens when you mix a little bit of magnesium with a sprinkle of alkyl and dash of halide? You get a pretty famous reagent named a Grignard reagent. Learn all about Grignard reagents and how to make them.

What Is a Grignard Reagent?

When you see the word, 'reagent,' can you think of a way to describe it? Maybe you said it is a chemical agent. How about something that is used in chemical reactions? Pretty close! Reagents are any substances or mixtures found in a chemical reaction. Most often, if we don't have a reagent then the reaction won't go the way it's designed to.

One type of reagent is called the Grignard reagent. Grignard reagents form when a magnesium metal binds to a carbon atom on an alkyl group containing a halogen atom. Let's break that down some. Grignard reagents love to donate their electrons to form chemical bonds with other molecules. Developed by famed French scientist Victor Grignard, these reagents help scientists perform a reaction where new carbon-to-carbon bonds can be created in organic structures.

Because Grignard reagents readily donate their electrons to form chemical bonds with other molecules, they are called nucleophiles. Grignard reagents are used for Grignard reactions. One such reaction is needed in the production of Tamoxifen, a breast cancer treatment drug.

Making a Grignard Reagent

In order to make a Grignard reagent, you need three substances: magnesium metal, an alkyl group, and a halogen. An alkyl group is any molecule that contains a carbon and hydrogen atom.

The formula for Grignard reagent is R-M-X. 'R' represents any alkyl group that can bind to 'M' the magnesium metal, (Mg). 'X' represents the halogen atom.

If you look at group 17 on a periodic table, you will find the home of halogens. They consist of atoms such as bromine, chlorine, and iodine. Note, if we smash together an alkyl group with a halogen atom we will make an alkyl halide. This term is often used when describing the ingredients required to make a Grignard reagent.

Because there are different halogens and alkyl groups, how can we determine which ones are the cream of the crop to use when preparing a Grignard reagent? Great question! Bromine and iodine are often used because of their reactivity. These two guys are very friendly. They love to mingle with alkyl groups and get the party started to make a Grignard reagent. But don't rule out chlorine! Chlorine, although not as reactive, can also be used to make Grignard reagents.

When choosing the alkyl group you certainly have many options. They can be:

  • Primary - where a carbon atom is attached to one non-hydrogen atom
  • Secondary - where the carbon atom is attached to two non-hydrogen atoms
  • Tertiary - where the carbon atom is attached to three non-hydrogen atoms


Using each of these ingredients along with the general equation, we can make a Grignard reagent.

General Equation For a Grignard Reaction

This general reaction can be done using specific ingredients, like bromine and ether.

Example of Specific Reaction of a A Grignard Reagent
GR specific

To unlock this lesson you must be a Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use

Become a member and start learning now.
Become a Member  Back
What teachers are saying about
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create an account