Synlett 2007(18): 2797-2800  
DOI: 10.1055/s-2007-991085
LETTER
© Georg Thieme Verlag Stuttgart · New York

Waste-Free and Environment-Friendly Uncatalyzed Synthesis of Dithiocarbamates under Solvent-Free Conditions

Najmedin Azizi*b, Forogh Ebrahimia, Elham Aakbaria, Fezzeh Aryanasaba, Mohammad R. Saidi*a
a Department of Chemistry, Sharif University of Technology, 11365 Tehran, Iran
Fax: +98(21)66012983; e-Mail: saidi@sharif.edu;
b Chemistry and Chemical Engineering Research Center of Iran, 14335 Tehran, Iran
Further Information

Publication History

Received 24 January 2007
Publication Date:
12 October 2007 (online)

Abstract

A mild, convenient, and practical one-pot procedure for the direct synthesis of dithiocarbamates has been developed by condensation of amines, CS2, and a Michael acceptor, under solvent-free conditions at room temperature in good to excellent yields.

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The reaction was very exothermic and should be controlled by slow addition of amine and maintaining the temperature by using an ice bath.

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Selected Spectroscopic DataTable 1, Entry 1: 1H NMR (500 MHz, CDCl3): δ = 0.92-0.96 (6 H, m), 2.53 (2 H, t, J = 6.7 Hz), 3.12 (2 H, t, J = 6.2 Hz), 3.42 (2 H, q, J = 6.7 Hz), 3.67 (2 H, t, J = 6.7 Hz). 13C NMR (125 MHz, CDCl3): δ = 9.4, 11.7, 18.2, 32.0, 47.2, 49.9, 118.6, 192.7.
Table 1, Entry 2: 1H NMR (500 MHz, CDCl3): δ = 1.30-1.51 (6 H, m), 2.74 (2 H, t, J = 6.2 Hz), 3.39 (2 H, t, J = 6.3 Hz), 3.75 (2 H, m), 4.12 (2 H, m). 13C NMR (125 MHz, CDCl3): δ = 18.5, 25.9, 32.2, 51.9, 53.4, 54.2, 118.7, 193.0. Anal. Calcd (%) for C9H14N2S2: C, 50.43; H, 6.58; N, 13.07. Found: C, 50.80; N, 12.92; H, 6.62.
Table 1, Entry 3: 1H NMR (500 MHz, CDCl3): δ = 1.72-1.92 (4 H, m), 2.66 (2 H, t, J = 6.5 Hz), 3.29 (2 H, t, J = 6.5 Hz), 3.43 (2 H, t, J = 6.7 Hz), 3.64 (2 H, t, J = 6.7 Hz). 13C NMR (125 MHz, CDCl3): δ = 18.6, 24.5, 26.2, 31.6, 51.1, 53.9, 55.5, 118.7, 190.0. Anal. Calcd for C8H12N2S2: C, 47.97; H, 6.04; N, 13.98. Found: C, 48.30; H, 5.82, N, 13.69.
Table 1, Entry 7: 1H NMR (500 MHz, CDCl3): δ = 2.82 (2 H, t, J = 6.2 Hz), 3.46 (2 H, t, J = 6.3 Hz), 4.88 (2 H, s), 7.26-7.39 (5 H, m), 8.02 (1 H, br s, NH). 13C NMR (125 MHz, CDCl3): δ = 18.9, 31.4, 51.5, 119.0, 128.3, 128.8, 129.7, 136.5, 196.0.
Table 1, Entry 10: 1H NMR (500 MHz, CDCl3): δ = 0.77 (3 H, t, J = 7.3 Hz), 1.07 (3 H, d, J = 6.4 Hz), 1.41-1.51 (4 H, m), 2.65 (2 H, t, J = 6.6 Hz), 3.35 (2 H, J = 6.7 Hz), 4.37-4.38 (1 H, m), 7.73 (1 H, br s, NH). 13C NMR (125 MHz, CDCl3): δ = 10.8, 18.5, 19.4, 29.7, 31.1, 55.1, 55.2, 119.1, 194.3.
Table 1, Entry 11: 1H NMR (500 MHz, CDCl3): δ = 0.93-0.99 (6 H, m), 2.47 (2 H, t, J = 6.4 Hz), 3.20 (2 H, t, J = 6.5 Hz), 3.44 (3 H, s), 3.45 (2 H, q, J = 6.9 Hz), 3.70 (2 H, q, J = 6.9 Hz). 13C NMR (125 MHz; CDCl3): δ = 11.7, 12.9, 31.7, 33.9, 46.9, 49.6, 51.6, 171.9, 194.4.
Table 1, Entry 12: 1H NMR (500 MHz, CDCl3): δ = 1.41-1.47 (6 H, m), 2.53 (2 H, t, J = 6.4 Hz), 3.42-4.01 (9 H, m). 13C NMR (125 MHz, CDCl3): δ = 24.5, 25.8, 31.8, 34.0, 44.3, 51.5, 51.8, 52.9, 172.1, 194.5. Anal. Calcd (%) for C10H17NO2S2: C, 48.55; N, 5.66; H, 6.93. Found: C, 48.70; N, 5.79; H, 6.95.
Table 1, Entry 13: 1H NMR (500 MHz, CDCl3): δ = 1.76-1.86 (4 H, m), 2.57 (2 H, t, J = 6.7 Hz), 3.28-3.46 (7 H, m), 3.64-3.66 (2 H, m). 13C NMR (125 MHz, CDCl3): δ = 24.5, 26.3, 31.2, 34.1, 50.8, 51.8, 55.2, 172.3, 191.7.
Table 1, Entry 15: 1H NMR (500 MHz, CDCl3): δ = 2.82 (2 H, t, J = 6.7 Hz), 3.52 (2 H, t, J = 6.7 Hz), 3.67 (3 H, s), 4.90 (2 H, s), 7.33-7.35 (5 H, m), 7.90 (1 H, br s, NH). 13C NMR (125 MHz, CDCl3): δ = 30.3, 34.6, 51.4, 52.3, 128.3, 128.6, 129.3, 135.7, 172.8, 197.7.
Table 1, Entry 17: 1H NMR (500 MHz, CDCl3): δ = 0.89 (3 H, t, J = 7.2 Hz), 1.19 (3 H, d, J = 5.3 Hz), 1.51-1.61 (2 H, m), 2.74 (2 H, t, J = 6.8 Hz), 3.44 (2 H, t, J = 6.8 Hz), 3.66 (3 H, s), 4.52 (1 H, m), 7.38 (1 H, br s, NH). 13C NMR (125 MHz, CDCl3): δ = 10.6, 20.9, 29.1, 30.9, 34.2, 52.1, 54.7, 54.8, 172.8, 196.0.
Table 1, Entry 19: 1H NMR (500 MHz, CDCl3): δ = 1.01-1.06 (6 H, m), 1.94 (3 H, s), 2.72 (2 H, t, J = 6.6 Hz), 3.23 (2 H, t, J = 6.6 Hz), 3.52 (2 H, q, J = 7.1 Hz), 3.79 (2 H, q, J = 7.1 Hz). 13C NMR (125 MHz, CDCl3): δ = 11.8, 12.7, 30.1, 30.6, 43.3, 46.9, 49.6, 195.2, 206.9.
Table 1, Entry 21: 1H NMR (500 MHz, CDCl3): δ = 1.38-1.76 (7 H, m), 2.53 (2 H, t, J = 6.1 Hz), 3.01-3.44 (6 H, m). 13C NMR (125 MHz, CDCl3): δ = 23.8, 25.9, 29.9, 43.1, 50.7, 55.1, 191.7, 206.3. Anal. Calcd (%) for C9H15NOS2: C, 49.73; H, 6.96; N, 6.44. Found: C, 49.53; H, 6.82; N, 6.61.
Table 1, Entry 25: 1H NMR (500 MHz, CDCl3-CCl4): δ = 1.58 (3 H, d, J = 6.8 Hz), 2.14 (3 H, s), 2.89 (2 H, t, J = 6.1 Hz), 3.40 (2 H, t, J = 6.1 Hz), 5.81 (1 H, q, J = 6.8 Hz), 7.26-7.35 (5 H, m), 8.18 (1 H, br s, NH). 13C NMR (125 MHz, CDCl3): δ = 21.3, 29.0, 30.4, 43.3, 56.4, 127.0, 128.2, 129.3, 141.7, 196.8, 207.6.
Table 1, Entry 28: 1H NMR (500 MHz, CDCl3): δ = 1.26-1.31 (6 H, m), 3.68-4.21 (6 H, m), 5.76 (1 H, dd, J = 4.1, 10.2 Hz), 7.24-7.69 (8 H, m), 8.00-8.01 (2 H, m). 13C NMR (125 MHz, CDCl3): δ = 127.9, 128.5, 128.7, 129.1, 129.6, 134.1, 137.6, 140.8, 190.8, 197.4.
Table 1, Entry 30: 1H NMR (500 MHz, CDCl3): δ = 1.93-2.05 (4 H, m), 3.58-4.02 (6 H, m), 5.83 (1 H, dd, J = 4.1, 9.8 Hz), 7.27-7.56 (8 H, m), 8.00 (2 H, d, J = 7.3 Hz). 13C NMR (125 MHz, CDCl3): δ = 24.6, 26.5, 51.0, 54.6, 55.3, 128.0, 128.6, 128.8, 129.0, 129.4, 133.6, 137.0, 140.0, 191.5, 197.4.