Use of the grignard solution, Chemistry

Assignment Help:

Use of the Grignard solution to prepare 2,2,6-trimethyl-5-phenylheptan-3-one:

Prepare a solution of your enone (5.64 g; 0.030 moles) in dry ether (30 mL) and add it to the dropping funnel. Add it dropwise, over 30 min, to the stirred and ice-cooled solution of 2-propyl magnesium bromide. When addition is complete, remove the slush-bath and continue stirring for a further 30 min.

Hydrolyse the mixture by pouring it cautiously onto a mixture of ammonium chloride (16 g) and crushed ice (70 g) in a beaker, stirring as you do so with a glass rod. When the ice has melted, separate the two layers and extract the aqueous layer with ether (2 x 50 mL; there is no need to use dry ether at this stage: why not?) keep the ether layer. Back-wash the combined ethereal layers with saturated brine (40 mL)

Dry the ether layer over anhydrous magnesium sulphate, filter and evaporate thoroughly (use a clean rotary evaporator!) to dryness, in a tared RB flask. Determine the weight of the crude product obtained.

Recrystallise your product (even if it is at present a liquid) from a mixture of ethanol/water (95:5, v/v), using 2 mL of solvent for each gram of product. If no crystals appear on cooling the filtered solution in ice, add a seed crystal of product (available from a demonstrator) to induce crystallisation. After allowing a thick precipitate to form, collect it on a Hirsch funnel, filtering rapidly to avoid redissolving. Pull the cake as dry as possible, then finally dry (24 hr) on a watch glass, in air, in a cupboard.

Related Discussions:- Use of the grignard solution

Block structure-many-electron atoms, The filling of the table defined above...

The filling of the table defined above leads to a natural division of the periodic table into blocks according to the outer electron configurations of atoms (see Fig. 2). All s blo

Platinichloride method for bases - chemical methods, Platinichloride Method...

Platinichloride Method for Bases - Chemical Methods Organic bases combine along with chloroplatinic acid, H 2 PtCl 6 to make insoluble platinichlorides, that on ignition, opt

Ayclalkanes.., perkin ring closure reaction of melonic ester with C2H5O-Na+...

perkin ring closure reaction of melonic ester with C2H5O-Na+

Define the term - local electric field and polarization, Define the term - ...

Define the term - Local electric field and Polarization Local electric field: It's the sum of the electric field from external sources and field of the dipoles within the spe

Maximum number of unpaired electrons, Which of the following metal ions wil...

Which of the following metal ions will have maximum number of unpaired electrons: (1) Fe +2                                (2) Co +2                        (3) Ni +2

Visualisation of hybrid orbitals - c atomic orbitals, Visualisation of hybr...

Visualisation of hybrid orbitals -C atomic orbitals Hybrid orbitals are the result of a model which combines atomic orbitals on a single atom in the ways that lead to a new se

How to define fast reactions, Fast reactions are those reactions that occur...

Fast reactions are those reactions that occur instantaneously. A fast reaction depends upon the reaction rates. These reactions are so fast that they occur as soon as the reactants

The number of orbitals in the fourth principal quantum no., The number of o...

The number of orbitals in the fourth principal quantum number will be: (1) 4               (2) 8        (3) 12               (4) 16 Ans: 16

Write Your Message!

Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd