ochem lab benzocaine

Question 1

structural similarities between anesthetics

Answer 1

aromatic residue, intermediate chain, amino group joined via an ester linkage

Question 2

benzocaine

Answer 2

ethyl ester of p-aminobenzoic acid

Question 3

role of h2so4

Answer 3

acid catalyst for fischer esterification

Question 4

formula

Answer 4

paminobenzoic acid+ ethanol makes benzocaine

Question 5

quaternary amine salt

Answer 5

four alkyl groups attached to nitrogen

Question 6

how many substituents in primary amine

Answer 6

1

Question 7

amines are _____ that can be protonated to form _____

Answer 7

orcanic bases that form amine salts (r-nh2 becomes rnh3+)

Question 8

increasing concentration of H ions does what

Answer 8

favors protonated amine

Question 9

decreasing h ions favors which side

Answer 9

free amine (nh2)

Question 10

how are protonated amines formed

Answer 10

reaction of an acid with the amine base

Question 11

free aminea are usually what?

Answer 11

oils reactive to air and co2

Question 12

are amines soluble in h20

Answer 12

not really so difficult to administer, but protonated amines are crystalline solids that can be purified and are soluble

Question 13

steps of reaction

Answer 13

p aminobenzoic acid is a free amine, when cominf into contact with h2so4 it makes the hydrosulfate salt which precipitates. upon heating, solid reacts with the solvent ethanol to produce the ester (protonated benzocaine)

Question 14

reaction between cooh group and ethanol is

Answer 14

a fischer esterification needing acid catalysis but amino group uses a large portion of sulfuric acid to give protonated amine

Question 15

why should ph be acidic enough

Answer 15

not enough acid to catalyze second reaction because amine takes up all the hydrogens

Question 16

role of sodium carbonate

Answer 16

neutralization reaction to precipitate benzocaine as a free amine (goes from protonated to free)