M. Koketsu et al. / Tetrahedron Letters 42 (2001) 6333–6335
6335
3. (a) Fregona, D.; Graziani, R.; Faraglia, G.; Caselato, U.;
Sitran, S. Polyhedron 1996, 15, 2523; (b) Boyle, P. D.;
Cross, W. I.; Godfrey, S. M.; McAuliffe, C. A.; Pritchard,
R. G.; Teat, S. J. J. Chem. Soc., Dalton Trans. 1 1999,
2845; (c) Boyle, P. D.; Godfrey, S. M.; Pritchard, R. G. J.
Chem. Soc., Dalton Trans. 1999, 4245.
(6H, t, J=6.8 Hz, CH3), 3.49 (2H, br s, CH2), 3.97 (2H, br
s, CH2), 6.48 (2H, br s, NH), 13C NMR (CDCl3): l 12.2,
42.9, 51.1, 176.6, 77Se NMR (CDCl3): l 209.8, MS (CI)
m/z=181 [M++1], HRMS (EI) calcd for C5H12N2Se
180.0165, found 180.0147. 1-Selenocarbamoylpiperidine
5d: Mp 145.0–146.2°C; IR (KBr) 3303, 3169, 1522 cm−1
,
4. Ishihara, H.; Koketsu, M.; Fukuta, Y.; Nada, F. J. Am.
1H NMR (DMSO-d6): l 1.47 (4H, m, CH2), 1.59 (2H, m,
CH2), 3.76 (4H, br s, CH2), 7.75 (2H, br s, NH), 13C NMR
(DMSO-d6): l 23.6, 25.3, 176.0, 77Se NMR (DMSO-d6): l
218.5, MS (CI) m/z=193 [M++1]. HRMS (EI) calcd for
C6H12N2Se 192.0165, found 192.01499. N,N-Diethyl-
thiourea 6b: Mp 99.2–100.6°C; IR (KBr) 3376, 3192, 1522
Chem. Soc., in press.
5. Intermediate 2a was isolated quantitatively. 1H NMR
(CDCl3): l 3.40 (3H, s, CH3), 3.76 (3H, s, CH3), 10.65
(1H, br s, NH), 11.14 (1H, br s, NH), 13C NMR (CDCl3):
l 42.8, 43.0, 195.9, MS (CI): m/z=107 [M++1-HCl].
6. The preparation of LiAlHSeH 2: to a solution of selenium
powder (0.80 g, 10.0 mmol) in dry THF (100 mL) was
added lithium aluminium hydride 1 (0.38 g, 10.0 mmol) at
0°C under an argon atmosphere. The mixture was stirred
for 30 min. The black selenium powder was consumed in
less than 10 min. The reaction mixture became a heteroge-
neous grayish suspension. The 2 is formed in situ and is
then ready for further reaction.
cm−1 1H NMR (DMSO-d6): l 1.06 (6H, t, J=6.8 Hz,
,
CH3), 3.53 (4H, br s, CH2), 7.10 (2H, br s, NH), 13C NMR
(DMSO-d6): l 12.6, 44.5, 179.8, MS (CI) m/z=133 [M++
1]. 1-Thiocarbamoylpiperidine 6d: Mp 127.4–129.1°C; IR
(KBr) 3334, 3188, 1510 cm−1, 1H NMR (DMSO-d6): l 1.45
(4H, m, CH2), 1.56 (2H, m, CH2), 3.69 (4H, br s, CH2),
7.25 (2H, br s, NH), 13C NMR (DMSO-d6): l 23.7, 25.3,
48.2, 180.2, MS (CI) m/z=145 [M++1].
7. Spectral data of selected compounds. N,N-Dimethylsele-
nourea 5a: Mp 172.2–172.8°C; IR (KBr) 3366, 3162, 1551
8. Koketsu, M.; Okayama, Y.; Aoki, H.; Ishihara, H. Het-
eroatom Chem., submitted.
1
cm−1, H NMR (CDCl3): l 3.18 (6H, br s, CH2), 7.60 (2H,
9. S-Methyl selenothiocarbamate 8: Mp 58.9–59.5°C; IR
br s, NH), 13C NMR (CDCl3): l 37.9, 45.3, 177.7, 77Se
NMR (CDCl3): l 230.4, MS (CI) m/z=153 [M++1],
HRMS (EI) calcd for C3H8N2Se 151.98522, found
151.98346. N,N-Diethylselenourea 5b: Mp 121.8–122.7°C;
IR (KBr) 3340, 3176, 1534 cm−1, 1H NMR (CDCl3): l 1.27
(KBr) 3275, 3122, 1636 cm−1 1H NMR (acetone-d6): l
,
2.61 (3H, s, CH3), 9.19 (1H, br s, NH), 9.53 (1H, br s,
NH), 13C NMR (aceton-d6): l 22.0, 204.9, 77Se NMR
(acetone-d6): l 554.2, MS (CI): m/z=156 [M++1], HRMS
(EI) calcd for C2H5NSSe 154.93076, found 154.93083.
.