Question

Draw an arrow pushing mechanism and find the theoretical yield for the Grignard reaction below using the following amounts of reagent with the given molecular weights:

565 microliters of 2-bromopropane (molecular weight = 123g/mol)

304 microliters of 4-methoxybenzaldehyde (molecular weight = 136.15g/mol)

molecular weight of product = 180.27g/mol

In this experiment, you will prepare the Grignard reagent isopropyl-magnesium bromide from 2-bromopropane. You will allow this Grignard reagent to react with 4-methoxy-benzaldehyde to form a secondary alcohol, 1-(4-methoxyphenyl)-2-methylpropan-1-ol. OH MgBr Mg Equation 5 HC CHE HO HC CH, Ether 2-bromopropane isopropyl magnesium bromide OCH OCH 4-methoxybenzaldehyde 1-(4-methoxyphenyl)- 2-methylpropan-1-ol

The limiting reagent is _____________.

Answer 1

Limiting reagent = 4-Methoxybenzaldehyde.

Thereotical yield = 0.450 grams.

mechanism: ma ing h 2-bromopropane OHL Hod product ♡ calculating moles; - 2-bromopropane - 565 microl. – КЪ 10o = 0.565 my & mass=volume x density = 0.565 ml x 1.31916m3 = 0.740 g masse in moles = 0.740g mw 123 g/mol = 0.00601 more 6 4-methasybenzaldehyde = 304 microl = 30 1000 0.304 mu . Mass & volume eme) x density = 0.304 me x 1.12 glome = 0.340 g

Mass .. moles = - = 0 340g - 0.00250 136.159, mols MW Now, in balanced reaction mole 2-bromopropan reacts arsty 4-methary benzaldehyde (ratio 1:1). setbasy benzaldehyde must reacts aneh 0.00250 mole 4-methoxybenzaldehyde m. with 0.00250 mole 2-bromopropane. But e 2 bromopropane. But there are mose amouud 7 2-6p. (0.00 66/ moles is present. Thesefese 2-bromo propose is excess reagent 4-methory benzaldehyde is einstity recgent. Limiting Reagent = 4-Methory benz avalehyde) cess reagent Theoretical yield. In bolenceel reaction mose 4-methany benzer. Clinting scaguts produce Imole product (Ratio 1:)). Therefore, 0.0020 mole 4. meth.bene. will produce 0.00250 more product mass & product & moks ymw - 0.00250 mole x 180.27 g more 0.450 , Theoretical yield = 0.450g/