602
G. FILSAK AND H. BUDZIKIEWICZ
solvent CDCl3, shifts υ ppm. NMR data are listed in the
sequence of the groups in the respective compound.
NMR, 1.14 (t, 7.4 Hz), 2.41 (q, 7.4 Hz), 2.41 (t, 7.3 Hz),
1.46 (quin), 1.30 (sex), 0.81 (t, 7.3 Hz). 13C NMR, 14.5,
25.2, 31.5, 31.1, 21.8, 13.4.
Syntheses
sec-Butyl ethyl sulfide (5). Synthesis as for 2 starting from
s-C4H9Br. Yield 31%, b.p. 75 °C (10 kPa). 1H NMR, 1.15
(t, 7.1 Hz), 2.44 (q, 7.4 Hz), 2.61 (sex), 1.15 (d, 6.7 Hz),
1.33–1.61 (m), 0.88 (t, 7.4 Hz). 13C NMR 14.7, 24.0,
41.0, 20.6, 29.5, 11.2.
n-Butyl methyl sulfide (1). In a 50 ml flask containing 20 ml
of degassed H2O under N2, 2 g of NaOH and 4.5 g of
n-C4H9SH are dissolved and 8.5 g of CH3I are added
drop by drop over 30 min under cooling with tap water.
After stirring the mixture overnight, 20 ml of diethyl ether
are added and the aqueous phase is extracted several
times with diethyl ether. The combined organic phases
are washed with dilute NaOH and twice with H2O. After
drying over MgSO4 the substance is purified by distil-
lation over a Vigreux column. Yield 4.0 g (77%), b.p.
Isobutyl ethyl sulfide (6). Synthesis as for 2 starting from
i-C4H9Br. Yield 45%, b.p. 75 °C (10 kPa). 1H NMR, 1.15
(t, 7.4 Hz), 7.39 (q, 7.4 Hz), 2.31 (d, 6.7 Hz), 1.70 (m),
0.89 (d, 6.6 Hz). 13C NMR, 14.7, 26.4, 40.9, 28.5, 21.9.
Ethyl isopropyl sulfide (7). Synthesis as for 2 starting from
i-C3H7Br. Yield 51%, b.p. 107 °C. 1H NMR, 1.15 (t,
7.4 Hz), 2.46 (q, 7.4 Hz), 2.85 (m), 1.17 (d, 6.7 Hz). 13C
NMR 14.7, 24.2, 34.1, 23.7.
1
120 °C. H NMR 2.02 (s), 2.48 (t, 7.3 Hz), 1.51 (quin),
1.34 (sex), 0.85 (t, 7.3 Hz). 13C NMR, 15.3, 33.8, 31.2,
21.8, 13.5.
Labeled compounds. The labeled butyl bromides were
prepared by standard methods from the corresponding
labeled butanols by reaction with PBr3. [1,1-2H]2-Butanol
was obtained by reduction of butyric acid anhydride with
LiA1D4. LiA1D4 reduction of propionic acid anhydride
gave [1,1-2H]2-propanol, which was treated with PBr3
to give [1,1-2H]2-propyl bromide, from which by a
Grignard reaction [2,2-2H]2-butyric acid was obtained and
subsequently reduced with LiA1H4. LiA1D4 reduction
of acetic acid anhydride gave [1,1-2H]2-ethanol, which
was transformed to [1,1-2H]2-ethyl bromide and to the
corresponding Grignard reagent, which was reacted with
ethylene oxide to give [3,3-2H]2-butanol. In the same
way, [4,4,4-2H]3-butanol was obtained starting from
CD3COOD. [3,3,4,4,4-2H]5-butan-2-ol was prepared by
reaction of C2D5MgBr with CH3CHO. [20,20,20,3,3,3-
2H]6-Isobutanol was prepared from acetone-d6 by
sec-Butyl methyl sulfide (3). Synthesis as for 1 starting from
1
sec-C4H9SH. Yield 65%, b.p. 112 °C. H NMR, 2.00 (s),
2.53 (sex), 1.20 (d), 1.36–1.63 (m), 0.92 (t, 7.4 Hz). 13C
NMR, 13.0, 24.8, 20.1, 11.3.
Isobutyl methyl sulfide (4). Synthesis as for 1 starting from
1
i-C4H9SH. Yield 75%, b.p. 111 °C. H NMR, 2.02 (s),
2.31 (d, 6.9 Hz), 1.76 (m), 0.92 (d, 6.6 Hz). 13C NMR
16.0, 43.6, 28.0, 21.9.
n-Butyl ethyl sulfide (2). To a solution of 5.6 g of KOH in
50 ml of C2H5OH in a 250 ml flask under tap water cool-
ing and N2, 6.2 g of C2H5SH and subsequently drop by
drop 13.7 g of n-C4H9Br are added slowly. The mixture
is refluxed for 30 min. After cooling to room temperature,
100 ml of H2O and 30 ml of diethyl ether are added.
1
Work-up as for 1. Yield 60%, b.p. 85 °C (10 kPa). H
Table 1. Molecular ion region of 1 6 and of their labeled analogs (normalized for 32S and corrected for natural 13C)
Cž
Compound
No.
[M ꢀ 2]
[M ꢀ 1]
M
[M C 1]
[M C 2]
CH3
CH3
CH3
CH3
CH3
CD3
CH3
CH3
CH3
CH3
CH3
S
S
S
S
S
S
S
S
S
S
S
CH2CH2CH2CH3
CD2CH2CH2CH3
CH2CD2CH2CH3
CH2CH2CD2CH3
CH2CH2CH2CD3
CH2CH2CH2CH3
13CH2CH2CH2CH3
CH.CH3/CH2CH3
CH.CH3/CD2CD3
CH2CH.CH3/2
1
0.0
0.0
0.0
1.4
0.7
0.0
0.0
0.0
0.3
0.0
1.2
2.1
2.8
4.5
7.4
1.9
1.8
11.3
1.0
16.1
2.4
7.4
100.0
100.0
100.0
100.0
100.0
100.0
100.0
100.0
100.0
100.0
100.0
0.7
0.6
1.3
25.2
14.4
1.0
0.2
0.7
0.0
0.7
1a
1b
1c
1d
1e
1f
3
3a
4
4a
0.3
0.0
6.3
2.0
0.7
0.0
0.0
0.0
CH2CH.CD3/2
0.0
C2H5
C2H5
C2H5
C2H5
C2H5
C2D5
C2H5
C2H5
C2H5
C2H5
C2H5
C2D5
S
CH2CH2CH2CH3
CD2CH2CH2CH3
CH2CD2CH2CH3
CH2CH2CD2CH3
CH2CH2CH2CD3
CH2CH2CH2CH3
13CH2CH2CH2CH3
CH.CH3/CH2CH3
CH.CH3/CD2CD3
CH2CH.CH3/2
2
0.0
0.0
1.4
1.5
1.7
0.0
0.0
0.0
0.6
0.0
3.2
0.0
1.5
2.3
3.9
7.6
3.3
5.2
10.7
0.7
17.8
2.5
8.5
100.0
100.0
100.0
100.0
100.0
100.0
100.0
100.0
100.0
100.0
100.0
100.0
0.0
0.9
1.5
26.4
14.3
0.9
1.2
0.7
0.5
1.0
S
S
S
S
S
S
S
S
S
S
S
2a
2b
2c
2d
2e
2f
5
5a
6
6a
6b
0.5
1.2
6.6
2.0
0.2
0.4
0.0
CH2CH.CD3/2
CH2CH.CH3/2
1.4
0.4
0.0
0.3
5.7
Copyright 1999 John Wiley & Sons, Ltd.
J. Mass Spectrom. 34, 601–610 (1999)