Organic Process Research & Development
Technical Note
is soluble in 30% HCl, n-butyl chloride is insoluble).
66.67 μL/min) and left the microreactor after 15 min of
reaction time by passing through a dynamic backpressure
regulator (pmax set to 18 bar) into the collection vial. After 30
min a total volume of 4 mL (0.894 mL of 1-butanol and 3.102
mL of 30% HCl) was processed. n-Butyl chloride was isolated
by phase separation from the aqueous phase and briefly dried in
1
Subsequently 20 μL aliquots were taken for H NMR (d -
6
acetone) analysis.
Synthesis of n-Hexyl Chloride under Microwave Batch
Conditions (Figure 2). Into a 2−5 mL cylindrical microwave
Pyrex process vial equipped with a magnetic stir bar were
placed 592 μL (485.4 mg, ∼4.75 mmol) of n-hexanol and 1508
μL (∼14.25 mmol) of 30% (w/w, ∼9.5 M) aqueous HCl. The
vial was sealed by capping with a Teflon septum fitted in an
aluminum crimp top and the sample heated in the microwave
reactor for 15 min (fixed hold time) at 180 °C (20 bar). After
the reaction time had elapsed, the mixture was cooled to 45 °C
by gas jet cooling. The organic layer was separated from the
a desiccator over (s) CaCl to provide 787 mg (87%) in >98%
2
1
purity; H NMR (d -acetone): δ = 0.89−0.94 (t, J = 15 Hz,
3H), 1.39−1.51 (m, 2H), 1.69−1.78 (m, 2H), 3.59−3.63 (t, J =
6
12 Hz, 2H, 2H).
ASSOCIATED CONTENT
Supporting Information
■
*
S
aqueous phase and dried in a desiccator over CaCl (s) to
2
1
provide 495 mg (86%) of n-hexyl chloride of >95% purity ( H
NMR, GC-FID). This sample could be further purified by bulb-
to-bulb microdistillation to provide 71% of pure product as a
1
colorless liquid; H NMR (300 MHz, CDCl ): δ = 0.89−0.94
AUTHOR INFORMATION
Notes
3
■
(
3
t, J = 15 Hz, 3H), 1.28−1.47 (m, 6H), 1.74−1.83 (m, 2H),
.53−3.58 (t, J = 15 Hz, 2H).
Synthesis of n-Butyl Chloride under Microwave Batch
Conditions (Figure 2). Into a 2−5 mL cylindrical microwave
Pyrex process vial equipped with a magnetic stir bar were
placed 470 μL (337.8 mg, ∼4.56 mmol) of n-butanol and 1630
μL (∼15.40 mmol) of 30% (w/w, ∼9.5 M) aqueous HCl. The
vial was sealed by capping with a Teflon septum fitted in an
aluminum crimp top and the sample heated in the microwave
reactor for 15 min (fixed hold time) at 180 °C (20 bar). After
the reaction time had elapsed, the mixture was cooled to 45 °C
by gas jet cooling. The organic layer was separated from the
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
This work was supported by a grant from the Christian
Doppler Research Foundation (CDG).
■
REFERENCES
■
(
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1
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3
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(
2
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́ ́
e
Conditions (Table 2). Five milliliters of 30% aqueous HCl
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1
́ ́
e
́
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4
(
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3
2
0 min a total volume of 4 mL (1.128 mL of 1-hexanol and
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2
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8
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in a desiccator over CaCl (s) to provide 927 mg (85%) in
(
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2
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̈
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for the Preparation of Alkyl Chlorides). EP 0789013 A1, 1996, CAN
1
>
3
95% purity; H NMR (CDCl ): δ = 0.89−0.93 (t, J = 12 Hz,
H), 1.32−1.46 (m, 6H), 1.74−1.83 (m, 2H), 3.53−3.57 (t, J =
3
15 Hz, 2H).
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were loaded into the PTFE loop module (Figure 3). By
pumping water (flow rate feed A: 51.7 μL/min) into the loop
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1
27:176173; (c) Wintz, S. (Degussa AG, Germany). Verfahren zur
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-
(n-butanol, flow rate 14.9 μL/min) was directly pumped into
1
(
the two-feed glass microreactor. The 1 mL glass microreactor
chip was heated to 180 °C in the chip heater and the reaction
mixture was pumped through the reactor (overall flow rate
Stereoselective Synthesis; Helmchen, G., Hofmann, R. W., Mulzer, J.,
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1
56
dx.doi.org/10.1021/op300273u | Org. Process Res. Dev. 2013, 17, 152−157