chapter 18 amines and neurotransmitters -...

Chapter 18–1

Chapter 18 Amines and Neurotransmitters Solutions to In-Chapter Problems 18.1 To determine whether an amine is 1o, 2o, or 3o, count the number of carbons bonded to the nitrogen

atom as in Example 18.1. A 1o amine has one C–N bond, and so forth.

NC6H5

CCH3CH2O

O

CH3a. b.H2N(CH2)3NH(CH2)4NH(CH2)3NH2

1o 2o 2o 1o3o

18.2 Label the amine and hydroxyl group in scopolamine, a drug used to treat motion sickness, as 1o, 2o,

or 3o as in Example 18.1.

NCH3

O C CHO

CH2OH

O

scopolamine

3° amine1° hydroxyl group

18.3 Methamphetamine is a 2° amine. Give the molecular shape around each atom by counting groups.

CH2CHNHCH3

CH3

(1)3 groupstrigonal planar

(2)4 groups

tetrahedral

(3)3 atoms

1 lone pairtrigonal

pyramidal

a. 2° amine b.

18.4 Name each amine as in Example 18.2.

a. CH3CH2CHCH3

NH2butane butanamine(4 C's)

2 1

CH3CH2CHCH3

NH2

Answer: 2-butanamine

b. CH3CH2CH2 NHCH3

propane3 C's

propanamine

CH3CH2CH2 NHCH3

1

N-methyl

Answer: N-methyl-1-propanamine

© 2013 by McGraw-Hill Education. This is proprietary material solely for authorized instructor use. Not authorized for sale or distribution in any manner. This document may not be copied, scanned, duplicated, forwarded, distributed, or posted on a website, in whole or part.

Amines and Neurotransmitters 18–2

N(CH3)2c.

6 C's in the ringcyclohexanamine

N(CH3)2

N,N-dimethyl

Answer: N,N-dimethylcyclohexanamine

d. (CH3CH2CH2CH2)2NH Answer: dibutylamine

2 butyl groups(4 C's)

18.5 Work backwards to draw the structure corresponding to each name.

d. N,N-diethylaniline

NHCH3

NH2

NH2

N

CH2CH3

CH2CH3

CH2CH3

CH3CH2

CH3CH2

a. N-methylaniline

b. m-ethylaniline

c. 3,5-diethylaniline

N-methyl

m-ethyl

1

3

5

3,5-diethyl

N,N-diethyl


h. N-propylaniline

CH3CH2CHCH2CH2CH3

NH2

CH3CH2CH2CH2CH2 NHCH3

O2N NH2

NCH3

CH3CH2NCH3

CH3

ONH2

NH2

CH2CH2CH3

HN

CH2CH2CH3

a. 3-hexanamine

b. N-methylpentylamine

c. p-nitroaniline

d. N-methylpiperidine

e. N,N-dimethylethylamine

!f. 2-aminocyclohexanone

g. 1-propylcyclohexanamine

3

N-methyl

p-nitro

N-methyl

N,N-dimethyl

12

2-amino

1

1-propyl

N-propyl


Chapter 18–3

18.7 Determine the compound in each pair with a higher boiling point, using the rules in Example 18.3.

(CH3)2CHCH2NH2a. CH3C

CH2CH3

Oor

a ketone with only C–H bondsa 1o amine with N–H bonds

intermolecular hydrogen bondinghigher boiling point

b. (CH3)2CHCH2NH2 or (CH3)2CHCH2OH

a 1o amine with N–H bondsintermolecular hydrogen bonding

a 1o alcohol with an O–H bondintermolecular hydrogen bonding

stronger intermolecular forceshigher boiling point

NH2 CH3orc.

a 1o amine with N–H bondsintermolecular hydrogen bonding

higher boiling point

hydrocarbon

18.8 Caffeine is soluble in the organic solvent CH2Cl2 because caffeine is organic and “like dissolves like.”

18.9 Nicotine has two heterocycles: pyridine and pyrrolidine.

N N

CH3

pyridine pyrrolidine

18.10 Draw both enantiomers of nicotine.

N N

CH3

chirality center

NNCH3

H

N

H

NCH3

enantiomers 18.11 Morphine contains a 3° amine.

O

HO

NCH3HO

N is bonded to three groups: 3° amine.



18.12 Identify the functional groups in heroin.

O

O

NCH3O

CCH3

O

CCH3

O

ester

3o amine

alkene

aromatic ring

ether

ester 18.13 Quinine has 11 trigonal planar carbon atoms [part (a), labeled with *] and nine tetrahedral carbon

atoms [part (b), all other C’s].

N

CH2=CH

CH

N

CH3O

HO

quinine*

**

**

* **

*

**

18.14 Draw the products when the amines are treated with HCl as in Example 18.4.

(CH3CH3NH3) + Cl–+

(CH3CH2)2NH2++ Cl–

(CH3CH2)3NH+ + Cl–a.

b.

c.CH3CH2NH2

(CH3CH2)2NH

HCl

HCl

HCl(CH3CH2)3N

18.15 Draw the products of each reaction.

CH3CH2CH2CH2 NH2 HCl+a. (CH3CH2CH2CH2 NH3)+ + Cl–

C6H5COOH(CH3)2NH +b. C6H5COO–(CH3)2NH2 ++

NH

H2O+c.N

OH–+

+

HH


Chapter 18–5

18.16 Draw the products of the reaction.

HO

HO CHCH2NHCH3OH

HO

HO CHCH2NH2CH3OH

+

HSO4–+

H2SO4

18.17 Name each ammonium salt as in Example 18.5.

a. (CH3NH3) Cl– b. [(CH3CH2CH2)2NH2] Br– c. [(CH3)2NHCH2CH3] CH3COO–

chloridederived from methylamine

methylammonium chloride

bromidederived from dipropylamine

dipropylammonium bromide

acetatederived from ethyldimethylamine

ethyldimethylammonium acetate 18.18 Ammonium salts are water-soluble solids. A water-insoluble amine can be converted to a water-

soluble ammonium salt by treatment with acid.

a. Cl–Br–(CH3CH2)3N b. [(CH3CH2)3NH] c. CH3CH2NH2 d. NH

H3° amine with 6 C's

water insolubleammonium saltwater soluble

1° amine with 2 C'swater soluble

ammonium saltwater soluble


a. Cl–Br– c.

b.

[(CH3CH2)3NH] NH

H

(CH3CH2NH3) HSO4–

(CH3CH2)3N NH

CH3CH2NH2

NaOH

NaOH

NaOH+ H2O + NaBr

+ H2O + NaHSO4+ H2O + NaCl

18.20 Draw the structure of each amine from which the ammonium salt is derived.

CHCH2 N CH3H

OHC

CCH2CH3CH2

O

CHCH3

N CH3CH3

HO

methadonephenylephrine

18.21 A quaternary ammonium salt like Bitrex has four R groups bonded to N, so there is no proton

available that can be removed to form an amine.



18.22 The chirality center in each compound is labeled.

CHCH2NH2HO

HOOH

norepinephrine

CH2CHNH2HO

HO

dopamine

CH2CHNH2HOCOOH

tyrosine

CH2CHNH2HOCOOH

HO

L-dopa

H

* = chirality center

*

*

*

achiral

18.23 COOH must be removed and OH must be added.

NH

HOCH2CH2NH2

serotonin

NH

CH2CHNH2

tryptophan

COOH

The COOH group is removed, and the OH group is added.

18.24 Serotonin, bufotenin, and psilocin have the same ring system with a two-carbon chain containing a

N atom bonded to it. They all contain an OH group bonded to the six-membered ring.

NH

HOCH2CH2N(CH3)2

NH

CH2CH2N(CH3)2OH

NH

HOCH2CH2NH2

2o 2o 2o

3o3o1o

serotonin bufotenin psilocin 18.25 To convert phenylephrine to methamphetamine requires the addition of a methyl group and

removal of two OH groups. 18.26 The atoms of 2-phenylethylamine are in bold in each compound.

CH3O

CH3O CH2CH2NH2

CH3O mescaline

a.

N

N

H

C CH3O

(CH3CH2)2N

LSD

b.


Chapter 18–7

18.27 Classify each alcohol and amine as 1°, 2°, or 3°. OH groups not labeled are phenols.

HO

HOCH2

CHCH2NHC(CH3)3

albuterol(Trade names: Ventolin, Proventil)

HO

HOCH2

CHCH2NH(CH2)6O(CH2)4

salmeterol(Trade name: Serevent)

OH OH

2° alcohol 2° alcohol

1° alcohol 1° alcohol2° amine 2° amine

18.28 Draw the complete structure for cimetidine.

CC

NCN

H CH

HH

CH

HS C

H

HCH

HNH

CNC N

NH

CH

HH

H

Solutions to End-of-Chapter Problems 18.29 To determine whether an amine or amide is 1o, 2o, or 3o, count the number of carbons bonded to

the nitrogen atom as in Example 18.1.

3° amine2° amide 18.30 To determine whether an amine or amide is 1o, 2o, or 3o, count the number of carbons bonded to

the nitrogen atom as in Example 18.1.

NN

OCH3

3° amine

3° amide

18.31 To determine whether an amine is 1o, 2o, or 3o, count the number of carbons bonded to the nitrogen atom as in Example 18.1.

CH3CHCH2CH2NHCH3CH3

N CH3a. b.

2o 3o



18.32 To determine whether an amine is 1o, 2o, or 3o, count the number of carbons bonded to the nitrogen atom as in Example 18.1.

CH3CCH2NH2CH3

a. b.

1oCH3

N(CH3)2

3o

18.33 Draw a structure to fit each description.

CH3CH2CH2CH2CH2NH2 CH3CH2CH2NCH2CH2CH3

HCH3CH2NCH2CH3

CH2CH3

CH2CH3+

a. b. c. d.N CH3

1° amineC5H13N

2° amineC6H15N

3° amineC6H13N

quaternary ammonium ion

C8H20N+

18.34 Draw a structure to fit each description.

HOCH2CH2CH2CH2NH2a.

1o alcohol 1o amine

b. CH3CHCH2NHCH3

OH

2o alcohol

2o amine

c. HOCCH2NH2

CH3

CH3

1o amine

3o alcohol

d. NCH3 CH2CH2OHCH3

3o amine

1o alcohol 18.35 Name each amine as in Example 18.2.

a. b.

N-ethyl-N-methylaniline

cyclohexane

cyclohexanamine

ethyl

methyl

aniline


Chapter 18–9


a.

b.

2 methyl groups

N,N-dimethylpentanamine

Cl NH2

m-chloro

m-chloroaniline

CH2CH2CH2CH2CH2 NCH3

CH3


CH3CH2 NH

CH2CH3a.

2 ethyl groups

Answer: diethylamine

CH3CH2CHCH2CH2CH2CH2CH3

NH2

b.1octane

(8 C's)octanamine

CH3CH2CHCH2CH2CH2CH2CH3

NH2

2 3

Answer: 3-octanamine

CH3CH2CH2CHCH2CH3

NHCH3c.

hexane(6 C's)

hexanamine

CH3CH2CH2CHCH2CH3

NHCH3

123

N-methylAnswer: N-methyl-3-hexanamine

CH3CHCH2CH2CH2CH2CH3

NHCH2CH3

d. Answer: N-ethyl-2-heptanamine

heptane(7 C's)

heptanamine

CH3CHCH2CH2CH2CH2CH3

NHCH2CH3 N-ethyl

21


CH3(CH2)6NH2a. Answer: 1-heptanamineheptane heptanamine(7 C's)

b. Answer: N-ethylcyclopentanamineNHCH2CH3

cyclopentane(5 C ring) N-ethyl



c. Answer: N-ethylpyrrolidineN

pyrrolidine N-ethyl

CH2CH3

d. Answer: N-ethyl-N-methyl-2-propanamineCH3CHCH3

N CH2CH3

CH3

propane(3 C's)

propanamine

CH3CHCH3

N CH2CH3

CH3

1 2 3

N-methylN-ethyl


CH3CH2CH2CH2CH2CH2CH2CH2CH2CH2NH2

N

NH2

Br

CH3CHCH2COOH

CH3CH2CH2CH2CH2CH2CHCH3

N(CH2CH2CH3)2

CH3CH2NHCH2CH2CH2CH2CH2CH3

NH2

f. N-ethylhexylamine

a. 1-decanamine

b. tricyclohexylamine

c. p-bromoaniline

d. 3-aminobutanoic acid

e. N,N-dipropyl-2-octanamine

p-bromo

3-amino

13

N,N-dipropyl

N-ethyl

3 cyclohexyl groups


NHCH2CH2CH2CH2CH3

CH3CHCCH3

CH3CHCH2CH2NH2

NH2

f. N-ethyl-N-propylcyclopentylamine

a. cyclobutylamine

b. 4-nonanamine

c. N-pentylaniline

d. 3-amino-2-butanone

e. 3-methyl-1-butanamine

3-amino 1

3

N-ethyl

NH2

CH3CH2CH2CHCH2CH2CH2CH2CH3

NH2

4

N-pentyl

O

CH3

13

N CH2CH2CH3

CH2CH3 N-propyl


Chapter 18–11

18.41 Draw the structures to illustrate the differences between N,N-dimethylaniline and 2,4-diethylaninline

N(CH3)2 NH2

CH2CH3CH3CH2

N,N-dimethylaniline 2,4-diethylaniline

3° amine 1° amine

18.42 Draw the structures to illustrate the differences between N-butylaniline and o-butylaniline.

NH(CH2)3CH3 NH2

CH2CH2CH2CH3

N-butylaniline o-butylaniline

2° amine 1° amine

18.43 Work backwards from the name to draw each ammonium salt.

c. ethyldimethylammonium hydroxide

[(CH3CH2CH2)2NH2]+ ++

Cl– (CH3CH2CH2CH2NH3) Br– CH3CH2N(CH3)2 OH–

H

a. dipropylammonium chloride b. butylammonium bromide

ethyl

dimethyl 18.44 Work backwards from the name to draw each ammonium salt.

c. ethylmethylammonium chloride

+CH3CH2NCH3

–ClH

a. cyclohexylammonium fluoride b. triethylammonium iodide

ethyl

methyl

NH3+

F– NHCH2CH3

CH3CH2

CH2CH3

+ I–

H

18.45 Draw and name the four amines of molecular formula C3H9N.

NCH3

CH3 CH3 CH3CH2CH2NH2 CH3CH2NHCH3

trimethylamine 1-propanamine N-methylethanamine

CH3CHNH2CH3

2-propanamine



18.46 Draw and name the eight constitutional isomers of molecular formula C4H11N. Identify the chirality center present in one of the amines.

CH3CH2CHCH3

NH2

CH3CH2CH2CH2NH2*

chirality center

1-butanamine 2-aminobutane

CH3CHCH2NH2

CH3

2-methyl-1-propanamine

CH3CCH3

CH3

NH2

2-amino-2-methylpropane

CH3CH2CH2NHCH3

N-methyl-1-propanamine

CH3CH2NHCH2CH3

diethylamine

CH3CHNHCH3

CH3

N-methyl-2-propanamine

CH3CH2NCH3

CH3

N,N-dimethylethanamine 18.47 Pyridine is capable of hydrogen bonding with water, so it is more water soluble than benzene.

Pyridine has a higher boiling point than benzene because it contains polar C–N bonds, while benzene is a nonpolar hydrocarbon.

18.48 CH3CH2CH2NH2 is water soluble because it is capable of hydrogen bonding with water.

CH3CH2CH2CH3 is not water soluble because it is a nonpolar hydrocarbon and cannot hydrogen bond to water.

18.49 Determine the compound in each pair with a higher boiling point, using the rules in Example

18.3.

a.

b.

c.CH3CH2CH2NH2 or CH3(CH2)7NH2

CH3(CH2)6OH or CH3(CH2)6NH2

CH2N(CH3)2 CH2CH2CH2NH2or

alcoholhigher

boiling point

amine

3 C amine 8 C aminehigher

boiling point 3° amineno N–H bonds

1° amineN–H bonds

higherboiling point

18.50 Determine the compound in each pair with the higher boiling point using the rules in Example

18.3.

a.

b.

c.

ketone aminehigher

boiling point

1° amine

(CH3CH2)2C O or (CH3CH2)2CHNH2

NHor

hydrocarbon aminehigher

boiling point

CH3CHCH2CHCH3

Cl NH2

or CH3CH2CH2CHCH3

NH3+

Cl–

ammonium salthigher

boiling point


Chapter 18–13

18.51 The hydrogen bond is drawn as a dashed line.

NCH2CH3

HCH2CH3

NCH3CH2

CH3CH2H

18.52 The hydrogen bond is drawn as a dashed line.

NCH3CH2

CH3CH2H

OH

H

18.53 Primary amines can hydrogen bond to each other, whereas 3o amines cannot. Therefore, 1o

amines have higher boiling points than 3o amines of similar size. Since all amines contain nitrogen atoms, any amine can hydrogen bond to water. Therefore, 1o and 3o amines have similar solubility properties.

18.54 CH3(CH2)5NH3

+Cl is more water soluble than CH3(CH2)5NH2 because the ammonium salt is an ionic solid and therefore soluble in water. CH3(CH2)5NH2 contains six carbons and is therefore not water soluble.

18.55 Draw the reaction of each amine with water by transferring a proton from H2O to the amine.

a. CH3CH2NH2 + H2O (CH3CH2NH3)+

+ OH–

+

b. (CH3CH2)2NH + H2O (CH3CH2)2NH2 + OH–

+

c. (CH3CH2)3N + H2O (CH3CH2)3NH + OH–

18.56 Draw the ammonium salt that is formed when each amine is treated with HCl.

+NH2 + HCla. NH3 Cl –

+CH2NHCH3 + HClb. CH2NH2CH3 Cl –

+N(CH2CH3)2 + HClc. NH(CH2CH3)2 Cl –




a. CH3CH2CH2N(CH3)2 + HCl CH3CH2CH2NH(CH3)2 + Cl–+

b. CH3CH2CHCH2CH3

NH2+ H2SO4 CH3CH2CHCH2CH3

NH3+ HSO4

–

+

c.N

+ HBrNH

+ Br–+

CH3CH2 NH

CH2CH3

CH2CH3

++d. NaOH CH3CH2 N CH2CH3

CH2CH3

+ H2O + Na+

18.58 Draw the products of each acid–base reaction.

a. + HCl + Cl–+N N

H

b. + H2SO4 + HSO4–

+

CH3CH2CHCH2CH3NHCH3

CH3CH2CHCH2CH3NH2CH3

c. + CH3COOH + CH3COO–+

CH3NH2 CH3NH3

CH3(CH2)5NH3+

+d. NaOH CH3(CH2)5NH2 + H2O + Na+


a.NH

CH2CH2CH3 N CH2CH2CH3

+

Cl–

H H

HCl

O

HO

NCH3HO

b. O

HO

NCH3HO

+

Cl–H

HCl


Chapter 18–15


+CH2CHNH2

CH3

a. + H2SO4 CH2CHNH3CH3

HSO4–

+

CH2CH2NH2b. + H2SO4 HSO4–HO

HO

CH2CH2NH3HO

HO

18.61 The heterocycle in both coniine and morphine is piperidine (labeled in bold).

O

HO

NCH3HO

morphine

NH

CH2CH2CH3

coniine

18.62 The pyrrolidine N is trigonal pyramidal because it is surrounded by four groups, three of which

are bonds and one of which is a lone pair of electrons. The pyridine N has only three groups around it, two of which are bonds and one of which is a lone pair. The pyridine N doesn’t have enough groups around it to be trigonal pyramidal.

N NCH3

trigonal pyramidaltrigonal planar 18.63 Caffeine is a mild stimulant, imparting a feeling of alertness after consumption. It also increases

heart rate, dilates airways, and stimulates the secretion of stomach acid. These effects are observed because caffeine increases glucose production, making an individual feel energetic.

18.64 Caffeine intake should be limited in pregnant and nursing mothers because excessive

consumption increases the risk of miscarriage and caffeine can pass into breast milk, possibly affecting the health of a newborn baby.

18.65 An alkaloid solution is slightly basic since its amine pulls off a proton from water, forming OH–

and an ammonium ion. 18.66 a. Morphine is found in poppies and is used as a pain reliever for people suffering from severe

chronic pain. b. Quinine is found in the bark of the cinchona tree and is used to treat malaria. c. Atropine is found in the nightshade plant and is used to increase heart rate.



18.67 Dopamine affects brain processes that control movement, emotions, and pleasure. Normal dopamine levels give an individual a pleasurable, satisfied feeling. Increased levels result in an intense “high.” Drugs such as heroin, cocaine, and alcohol increase dopamine levels. When there is too little dopamine in the brain, an individual loses control of fine motor skills and Parkinson’s disease results.

18.68 Patients with Parkinson’s disease cannot be treated by giving them dopamine, even though the

disease results from low dopamine levels, because dopamine does not cross the blood–brain barrier.

18.69 Serotonin plays an important role in mood, sleep, perception, and temperature regulation. We get

sleepy after eating a turkey dinner on Thanksgiving because the unusually high level of tryptophan in turkey is converted to serotonin. A deficiency of serotonin causes depression.

18.70 Two examples of SSRIs are fluoxetine (Prozac) and sertraline (Zoloft). They combat depression

by inhibiting the reuptake of serotonin by the presynaptic neuron. 18.71 Dopamine [part (a)] and norepinephrine [part (b)] are derived from tyrosine, serotonin [part (c)] is

derived from tryptophan, and histamine [part (d)] is derived from histidine. 18.72 A neurotransmitter is a chemical messenger that transmits nerve impulses from one nerve cell

(neuron) to another cell. A hormone is a compound produced by an endocrine gland, which then travels through the bloodstream to a target tissue or organ.

18.73 The atoms of 2-phenylethylamine are labeled in bold in the compounds below.

CH2CH2CH2NH2a. b. c.C

CH3

CH3

CH2N(CH3)2 CH2HN

not a derivative of2-phenylethylamine

18.74 The atoms of 2-phenylethylamine are labeled in bold in the compounds below.

a. b. c.CCH3

CH3

C CH2CH2

not a derivative of2-phenylethylamine

CH3

NHCH3

CH3 CH2NH N

18.75 The atoms of 2-phenylethylamine are labeled in bold.

CH2CNH2

CH3

CH3


Chapter 18–17

18.76 The atoms of 2-phenylethylamine are labeled in bold.

CHCH2NHC(CH3)3HO

HOCH2

OH

18.77 Chlorpheniramine is an example of an antihistamine. Antihistamines bind to the H1 histamine

receptor, but they evoke a different response than histamine. An antihistamine like chlorpheniramine or diphenhydramine, for example, inhibits vasodilation, so it is used to treat the symptoms of the common cold and environmental allergies.

18.78 Cimetidine is an anti-ulcer drug. It binds to the H2 histamine, thus reducing acid secretions in the

stomach. 18.79 Answer each question about benzphetamine.

CH2CHNCH2

CH3

CH3

chirality center

3o aminea. and b.

CC NCH2

CH3

H CH3

CCH2N C

CH3

HCH3

H

H

H

H

c.

enantiomers

CH2CHNH2

CH3

CH3

CH2

d.1° amine

constitutional isomer

CH2CH2N

CH2

e.CH3

CH3

3° amineconstitutional isomer

f. CH2CHNHCH2

CH3

CH3

+

Cl– benzphetamine hydrochloride



CH2CHNCH2CH3

CH3

+ CH3COOH CH2CHNHCH2CH3

CH3

++

g. CH3COO–

18.80 Answer each question about phentermine.

1o amineCH2CNH2

CH3

CH3

a.

CH2CNH2

CH3

CH3

tetrahedral

tetrahedral

trigonal pyramidal

trigonal planar

b.

CH2CHCH2NH2

CH3

c.

CH2CHNHCH3

CH3

d.

CH2CNH3

CH3

CH3

e. Br–+

CH2CNH2

CH3

CH3

f. CO

HO+ CH2CNH3CH3

CH3

–OCO

++

18.81 Answer the questions about Ritalin.

CH

COOCH3

HN

2o amine

ester

aromatic ring

a., b., and c.

chirality center

CH

COOCH3

N+

Cl–e.

d. 2-phenylethylamine in bold

HH


Chapter 18–19

18.82 Answer the questions about seldane.

(CH3)3C CHCH2CH2CH2

OHN C

OH

2° alcohol

aromatic ring

aromatic ring

3° amine 3° alcohol

a., b., c., d., and e.

quaternary carbonchirality center

(CH3)3C CHCH2CH2CH2OH

N COH

f.+

Cl–

18.83 Work backwards to draw the structure of the amine and carboxylic acid that are used to form Chlortrimeton, an ammonium salt.

CHCH2CH2N(CH3)2

N

ClH

C CH

HOOC COO–

H

+

chlorpheniramine maleateChlortrimeton

CHCH2CH2N(CH3)2

N

ClC C

H

HOOC COOH

H

18.84 Draw the structure of the dextromethorphan hydrobromide.

CH3O

NHCH3

+ Br–

18.85 A vasodilator dilates blood vessels and a bronchodilator dilates airways in the lungs. Histamine is

a vasodilator and albuterol is a bronchodilator. 18.86 Antihistamines that cause drowsiness are able to cross the blood–brain barrier and bind to H1

receptors in the central nervous system. Antihistamines that do not cause drowsiness also bind to H1 receptors, but they are unable to cross the blood–brain barrier and bind to the H1 receptors in the central nervous system.



18.87 Albuterol will exist in the ionic form in the stomach (lower pH) and in the neutral form in the intestines.

HO

HOCH2

CHCH2NHC(CH3)3

OHHO

HOCH2

CHCH2NH2CH(CH3)3

OH +

ionic form neutral form

albuterol 18.88 Eating a poppy seed bagel can produce a positive test in a drug screening because poppy seeds

contain morphine. 18.89 Heroin has two esters, which can be made from the two OH groups in morphine. Add acetic acid

(CH3COOH) and H2SO4 to make the two esters in heroin.

O

HO

NCH3HO

O

O

NCH3O

CCH3

O

morphine heroin

CCH3

O

Both OH groups are converted to esters.

CH3COOHH2SO4

18.90 The compound that might cause the odor that allows for heroin detection is acetic acid, the main

ingredient in vinegar.

O

O

NCH3O

CCH3

O

heroin

CCH3

O+ 2 H2O C

O

CH3 OHO

HO

NCH3HO

+

acetic acid(vinegar)

2


chapter 18 amines and neurotransmitters -...

Documents