Pentanols

Pentanols (also amyl alcohols from Latin amylum, starch) are alcohols with a hydroxyl group  (–OH) and the general empirical formula C ₅ H ₁₂ O. There are eight constitutional isomers , three of which are chiral . Pentanols have characteristic smells and, with the exception of the solid neo- pentanol (2,2-dimethyl-1-propanol), are colorless liquids with a density of 0.81 g · cm ⁻³ . They are flammable and harmful if inhaled. Some pentanols such as 1-pentanol, 3-methyl-butan-1-ol and 2-methyl-butan-1-ol are found in fusel oils and have harmful effects on humans.

Pentanols are used as solvents and are used for the synthesis of amyl acetate ( pentyl acetates ), which are used as technical solvents for various plastics and as flavorings and aromas. So z. B. Isoamyl alcohol as a solvent for fats, oils and resins.

2-Methylbutan-2-ol was previously used as a sleep aid under its old name amylene hydrate , but has not been used as such for a long time.

The oxidation of the primary pentanols ( n- pentanol, isopentanol, 2-methyl-1-butanol and neopentyl alcohol) leads to the pentanals and the pentanoic acids . The oxidation of the secondary pentanols (2-pentanol, 3-pentanol and 3-methyl-2-butanol) leads to the pentanones . The oxidation of the tert- pentanol leads to the destruction of the carbon structure.

Structure and properties

Pentanols
Surname	Pentan-1-ol	Pentan-2-ol	Pentan-3-ol	2-methyl-butan-1-ol
other names	1-pentanol , n pentanol, n -amyl alcohol, pentyl alcohol	2-pentanol , sec -amyl alcohol, 2-pentyl alcohol	3-pentanol , 3-amyl alcohol, 3-pentyl alcohol, diethyl carbinol	2-methyl-1-butanol , 2-methylbutyl alcohol
Structural formula		(chiral)		(chiral)
CAS number	71-41-0	6032-29-7	584-02-1	137-32-6
PubChem	6276	22386	11428	8723
Molecular formula	C 5 H 12 O
Molar mass	88.15 g mol −1
Brief description	colorless liquids
Melting point	−78 ° C	−50 ° C	−8 ° C	−70 ° C
boiling point	138 ° C	119 ° C	116 ° C	129 ° C
Solubility in water	22 g / l (20 ° C)	166 g / l (20 ° C)	55 g / l (30 ° C)	36 g / l (20 ° C)
Pentanols (continued)
Surname	2-methyl-butan-2-ol	3-methyl-butan-1-ol	3-methyl-butan-2-ol	2,2-dimethyl-propan-1-ol
other names	2-methyl-2-butanol , tert -pentanol, tert -pentyl alcohol, amylene hydrate	3-methyl-1-butanol , isopentyl alcohol, iso- amyl alcohol , isoamyl alcohol, isopentanol	3-methyl-2-butanol , sec- isoamyl alcohol, 2-isopentanol	2,2-dimethyl-1-propanol , neo- pentanol, neopentyl alcohol
Structural formula			(chiral)
CAS number	75-85-4	123-51-3	598-75-4	75-84-3
PubChem	6405	31260	11732	6404
Molecular formula	C 5 H 12 O
Molar mass	88.15 g mol −1
Brief description	colorless liquids			colorless solid
Melting point	−8 ° C	−117 ° C	−117 ° C	53 ° C
boiling point	102 ° C	131 ° C	112 ° C	113 ° C
Solubility in water	118 g / l (20 ° C)	30 g / l (20 ° C)	53.3 g / l (25 ° C)	40 g / l (20 ° C)

Individual evidence

1. ↑ ^{a b} Entry on pentanol, isomers in the GESTIS substance database of the IFA , accessed on July 3, 2013(JavaScript required) .
2. ^ Harry Auterhoff : Textbook of Pharmaceutical Chemistry , Wissenschaftliche Verlagsgesellschaft, Stuttgart 1968.
3. ↑ ^{a b c} Entry for CAS no. 71-41-0 in the GESTIS substance database of the IFA , accessed on July 3, 2013(JavaScript required) .
4. ↑ ^{a b c} Entry for CAS no. 6032-29-7 in the GESTIS substance database of the IFA , accessed on July 3, 2013(JavaScript required) .
5. ↑ ^{a b c} Entry for CAS no. 584-02-1 in the GESTIS substance database of the IFA , accessed on July 3, 2013(JavaScript required) .
6. ↑ ^{a b c} Entry for CAS no. 137-32-6 in the GESTIS substance database of the IFA , accessed on March 28, 2009(JavaScript required) .
7. ↑ ^{a b c} Entry for CAS no. 75-85-4 in the GESTIS substance database of the IFA , accessed on May 23, 2018(JavaScript required) .
8. ↑ ^{a b c} Entry for CAS no. 123-51-3 in the GESTIS substance database of the IFA , accessed on March 28, 2009(JavaScript required) .
9. ↑ ^{a b c} Entry for CAS no. 598-75-4 in the GESTIS substance database of the IFA , accessed on May 24, 2018(JavaScript required) .
10. ↑ ^{a b c} Entry for CAS no. 75-84-3 in the GESTIS substance database of the IFA , accessed on July 3, 2013(JavaScript required) .