Question

label the ir spectrum for Benzocaine and it's functional groups. Thank you

fethyl 4-aminobenzoate (Benzocaine) 10/31/2013 CH11NO2 mp 88 92 C 3500 4000 2000 3000 2500 1500 1000 Wavenumbers (cm-1) %Transmittance 30 3419 3222 2964 9962 O062 1922 6/91 E69 sesi 1514 1574 zEE 60E 99E 00 612

Answer 1

Benzocaine is a organic compound which has two functional groups and a benzene moiety. The structure of the compound is as follows:

  

CH3 NH2 Benzocaine

In the above structure of the compound, it has a primary amine (-NH₂) and ester (-CO₂CH₂CH₃) functional groups which are para-substituted to the benzene ring. So, we can see the various type signals in the IR spectrum.

IR spectra analysis of benzocaine

• Here we have a primary amine which is attached to the benzene ring. So, in the IR spectra, there is a doublet at 3419 and 3348 cm-1 region. Which is corresponding to the N-H stretch of primary amine
• At 3222 cm-1 there is a shoulder band which is an overtone of the N-H bend vibration.
• Around 2964 to 2900 cm-1 there is C-H stretch vibration of sp2 and sp3 carbon.
• At 1679 cm-1 there is a aryl ester C=O carbonyl stretch.
• 1595 cm-1 region there is a broad signal of primary amine N-H bond
• Around 1633 and 1590 region there is C=C stretching vibration.
• Near 770 cm-1 there is a single signal which is corresponding to the para-substituted benzene
• C-N stretch appears around 1213 cm-1 region
• C-O stretch band of ester gives two or more bands. One is stronger and broad than the other band. Which occurs in the range of 1170 to 1109 region.

Therefore, The all the above details given for the IR spectra is matches with the compound Benzocaine