G. Kaupp et al.
FULL PAPER
246 ± 2488C); 1H NMR (CDCl3/[D6]DMSO): d 7.76 (m, 2H), 7.41 (m,
[1] W. T. Bradner, D. A. Clarke, Cancer Research 1958, 18, 299; M.
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[2] J. R. Robinson, W. H. Brown, Can. J. Chem. 1951, 29, 1069.
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[5] E. W. Ainscough, E. N. Baker, M. L. Brader, A. M. Brodie, S. L.
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[7] M. Cariou, J. Simonet, Can. J. Chem. 1991, 69, 861.
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[9] V. M. Zabrovskij, G. P. Khocot, Chem. Heterocycl. Compd. (Engl.
Transl.) 1970, 6, 1456.
[10] R. W. Stephens, L. A. Domeier, Synth. Commun. 1991, 21, 2025.
[11] J. Haginiwa, J. Pharm. Soc. Jpn. 1953, 73, 1310; Chem. Abstr. 1955,
298.
[12] H. Gehlen, Liebigs Ann. Chem. 1949, 563, 185; the structure of 14a
was erroneously not assigned to the product in this paper.
[13] M. Mano, T. Seo, T. Matsuno, K. Imai, Chem. Pharm. Bull. 1976, 24,
2871.
[14] E. Grigat, R. Pütter, Angew. Chem. 1967, 79, 219; Angew. Chem. Int.
Ed. Engl. 1967, 6, 206; E. Grigat, Angew. Chem. 1972, 84, 1008; Angew.
Chem. Int. Ed. Engl. 1972, 11, 949.
[15] E. Vowinkel, H.-J. Baese, Chem. Ber. 1974, 107, 1213.
[16] K. Goliash, E. Grigat, R. Puetter (to Bayer AG), Ger. Offen. 1965,
1195743; Chem. Abstr. 1966, 64, 15795g.
[17] T. G. Levi, Gazz. Chim. Ital. 1931, 61, 383.
[18] J. Kinugawa, M. Ochiai, H. Yamamoto, Yakugaku Zasshi 1963, 83,
1086; Chem. Abstr. 1964, 60, 8026h.
[19] M. Saneyoshi, G. Chihara, Chem. Pharm. Bull. 1967, 15, 909.
[20] T. Zsolnai, Arzneimittelforsch. 1971, 21, 121; review of pharmaceutical
and synthetic applications of thiocyanates: D. Knoke, K. Kottke, R.
Pohloudek-Fabini, Pharmazie 1973, 28, 574; 617.
[21] M. Hesse, H. Meier, B. Zeeh, Spektroskopische Methoden in der
organischen Chemie, Thieme, Stuttgart, 1991, p. 45.
[22] D. E. Ben Efraim, in The Chemistry of Cyanates and Their Thio
Derivatives, Part 1 (Ed.: S. Patai), Wiley, Chichester, 1977, p. 194 and
202.
3H), 7.04 (s, 2H).
2-Amino-5-(p-tolyl)-1,3,4-oxadiazole (14b): Solid 4-methylbenzohydrazide
(12b) was treated with BrCN to give 100% of the hydrobromide 13b which
was washed with 5% Na2CO3 solution to give 14b. Yield: 100%; m.p. 277 ±
2798C (ref. [13]: m.p. 278 ± 2808C); 1H NMR (CDCl3/[D6]DMSO): d 7.65
(AA'BB', 2H), 7.22 (BB'AA', 2H), 6.89 (s, 2H), 2.34 (s, 3H).
2-Amino-5-(p-hydroxyphenyl)-1,3,4-oxadiazole (14c): Solid 4-hydroxyben-
zohydrazide (12c) was treated with BrCN to give 100% of the hydro-
bromide 13c which was washed with 5% Na2CO3 solution to give 14c.
Yield: 99%; m.p. 2738C (ref. [13]: m.p. 274 ± 2768C); 1H NMR (CDCl3/
[D6]DMSO): d 7.61 (AA'BB', 2H), 6.80 (BB'AA', 2H), 6.08 (s, 2H).
4-Methoxyphenylcyanate (16a): Solid potassium 4-methoxyphenolate
(15a) was treated with ClCN (or BrCN) to give a mixture of KCl (KBr)
and 16a; yield: 100% (100%). Pure 16a was obtained after removal of KCl
(KBr) by washing with water. M.p. 328C (ref. [15]: m.p. 29 ± 318C); IR
(KBr): nÄ 2278, 2238 (C N), 1176 cm 1 (C-O-C).
ꢀ
3,4-Dimethoxyphenylcyanate (16b): Solid potassium 3,4-dimethoxypheno-
late (15b) was treated with ClCN (or BrCN) to give a mixture of 16b and
KCl (KBr); yield: 100% (100%). Pure 16b was obtained after removal of
KCl (KBr) by washing with water. M.p. 60 ± 628C; IR (KBr): 2273, 2238
1
(C N), 1172 cm (C-O-C); 1H NMR (CDCl3): d 6.88 (m, 2H), 6.80 (s,
ꢀ
1H), 3.79 (s, 6H); 13C NMR (CDCl3): d 150.13, 147.60, 146.76, 111.37,
109.17, 106.25, 99.88, 56.32, 56.29; HR-MS (CI, isobutane) calcd for
C9H9NO3H: 180.0643; found 180.0641.
4-Cyanatobenzaldehyde (16c): Solid potassium 4-formylphenolate (15c)
was treated with ClCN (or BrCN) to give a mixture of 16c and KCl (KBr);
yield: 100% (100%). The mixture was extracted with dry CH2Cl2, the
solvent evaporated, and the residue dried in a vacuum to give pure 16c.
Yield: 98%; m.p. 538C (ref. [35]: m.p. 548C); IR (KBr): nÄ 2268, 2153
1
ꢀ
(C N), 1214 cm (C-O-C).
4-Formylphenylurethane (17c): A mixture of 16c and KCl (280 mg) from
the above experiment was stirred for 10 min with water (20 mL). The
mixture was filtered and dried to give 17c. Yield: 204 mg (99%); m.p.
1
2278C; IR (KBr): nÄ 3278 (N H), 1665, 1605 cm (C O); 1H NMR
(CDCl3): d 9.60 (s, 1H), 7.51 (d, 2H), 6.68 (d, 2H); HR-MS calcd for
C8H7NO3: 165.0424; found 165.0426.
2-Nitrophenylcyanate (16d) and 2-nitrophenylurethane (17d): Solid po-
tassium 2-nitrophenolate hemihydrate (15d) was treated with ClCN (or
BrCN) to give a mixture of 16d and KCl (KBr) that contained small
[23] G. Kaupp, Supermicroscopy in Supramolecular Chemistry: AFM,
SNOM, and SXM, in Comprehensive Supramolecular Chemistry,
Vol. 8 (Ed.: J. E. D. Davies), Elsevier, Oxford, 1996, pp. 381 ± 423; G.
Kaupp, Chem. Unserer Zeit 1997, 31, 129; G. Kaupp, A. Herrmann, J.
Prakt. Chem./Chem. Ztg. 1997, 339, 256; G. Kaupp, J. Boy, J.
Schmeyers, J. Prakt. Chem./Chem. Ztg. 1998, 340, 346.
[24] G. Kaupp, J. Schmeyers, Angew. Chem. 1993, 104, 1656; Angew. Chem.
Int. Ed. Engl. 1993, 32, 1587; A. Herrmann, G. Kaupp, T. Geue, U.
Pietsch, Mol. Cryst. Liq. Cryst. 1997, 293, 261.
quantitities of 17d; IR (KBr): nÄ 2237, 2203 (C N), 1203 cm 1 (C-O-C). If
ꢀ
the mixture was stirred with water for 5 min then 17d was obtained after
filtration and drying. Yield: 99%; m.p. 131 ± 132 (ref. [36]: m.p. 134 ±
1
1368C); IR (KBr): nÄ 3351 (N H), 1703 cm (C O).
Benzoxazole-2-thiocyanate (19a): Solid sodium benzoxazole-2-thiolate
(18a) was treated with ClCN (or BrCN). The product was washed with
water and dried to give pure 19a. Yield: 100% (100%); m.p. 738C
1
ꢀ
(ref. [16]: m.p. 74 ± 758C); IR (KBr): nÄ 2176 cm (C N).
Â
[25] A. Escande, J. L. Galigne, Acta Crystallogr. B 1974, 30, 1647.
Benzothiazole-2-thiocyanate (19b): Solid sodium benzothiazole-2-thiolate
(18b) was treated with ClCN (or BrCN). The product was washed with
[26] S. Ashfaquzzaman, A. K. Pant, Acta Crystallogr.
B 1979, 35,
water and dried to give pure 19b. Yield: 100% (100%); m.p. 848C
1394.
1
(ref. [17]: m.p. 85 ± 878C); IR (KBr): nÄ 2167 cm (C N); 1H NMR
[27] A. Kallel, B. H. Amor, I. Svoboda, H. Fuess, Z. Kristallogr. 1992, 198,
137.
[28] G. Kaupp, Mol. Cryst. Liq. Cryst. 1994, 242, 153.
[29] G. Kaupp, A. Herrmann, J. Prakt. Chem./Chem.-Ztg. 1997, 339,
256.
[30] G. Kaupp, D. Matthies, C. de Vrese, Chem. Ztg. 1989, 113, 219; G.
Kaupp, U. Pogodda, J. Schmeyers, Chem. Ber. 1994, 127, 2249; G.
Kaupp, U. Pogodda, unpublished results.
[31] G. Kaupp, J. Schmeyers, J. Org. Chem. 1995, 60, 5494.
[32] G. Kaupp, J. Schmeyers, U. Pogodda, M. Haak, T. Marquardt, M.
Plagmann, Thin Solid Films 1995, 264, 205.
ꢀ
(CDCl3): d 7.96 (1H), 7.83 (1H), 7.51 (1H), 7.41 (1H).
Pyrimidine-2-thiocyanate (19c): Solid sodium pyrimidine-2-thiolate (18c)
was treated with ClCN (or BrCN). The product was washed with water and
dried to give pure 19c. Yield: 100% (100%); m.p. 1068C (ref. [18]: m.p.
107 ± 1098C); IR (KBr): nÄ 2173 (C N); 1H NMR (CDCl3): d 8.58 (d,
ꢀ
2H), 7.08 (t, 1H).
Purine-6-thiocyanate (19d): Solid sodium purine-6-thiolate (18d) was
treated with ClCN (or BrCN). The product was washed with water and
dried to give pure 19d. Yield: 100% (100%); m.p. > 2208C (decomp)
1
(ref. [19]: m.p. 225 ± 2268C); IR (KBr): nÄ 2182 cm (C N); 1H NMR
ꢀ
[33] G. Kaupp, M. Plagmann, J. Photochem. Photobiol. A: Chem. 1994, 80,
399.
(CDCl3/[D6]DMSO): d 8.82 (s, 1H), 8.48 (s, 1H).
[34] F. Kurzer, J. Chem. Soc. 1950, 3269.
Acknowledgments: This work was supported by the Fonds der Chemischen
Industrie. We thank BASF for generous gifts of chemicals and M. Kramer
for experimental help.
[35] E. Grigat, R. Pütter, Chem. Ber. 1964, 97, 3012.
[36] Y. Iwakura, Y. Ishizuka, T. Saito, Nippon Kagaku Zasshi 1955, 76,
1108; Chem. Abstr. 1957, 51, 17750.
Received: April 28, 1998 [F1125]
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