{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,23]],"date-time":"2025-10-23T16:25:17Z","timestamp":1761236717945},"reference-count":16,"publisher":"Elsevier BV","issue":"14","license":[{"start":{"date-parts":[[1997,4,1]],"date-time":"1997-04-01T00:00:00Z","timestamp":859852800000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/www.elsevier.com\/tdm\/userlicense\/1.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Tetrahedron Letters"],"published-print":{"date-parts":[[1997,4]]},"DOI":"10.1016\/s0040-4039(97)00400-0","type":"journal-article","created":{"date-parts":[[2002,7,25]],"date-time":"2002-07-25T06:09:56Z","timestamp":1027577396000},"page":"2557-2560","source":"Crossref","is-referenced-by-count":27,"title":["Pyrimidine and Pyrimidone Derivatives of [60]Fullerene"],"prefix":"10.1016","volume":"38","author":[{"given":"Augusto C","family":"Tom\u00e9","sequence":"first","affiliation":[]},{"given":"Roger F","family":"Enes","sequence":"additional","affiliation":[]},{"given":"Jos\u00e9 A.S","family":"Cavaleiro*","sequence":"additional","affiliation":[]},{"given":"Jos\u00e9","family":"Elguero","sequence":"additional","affiliation":[]}],"member":"78","reference":[{"key":"10.1016\/S0040-4039(97)00400-0_BIB1","doi-asserted-by":"crossref","unstructured":"a) Hirsch, A. Synthesis, 1995, 895\u2013913; b) Hirsch, A. \u201cThe Chemistry of the Fullerenes\u201d, Thieme, New York, 1994","DOI":"10.1055\/s-1995-4046"},{"key":"#cr-split#-10.1016\/S0040-4039(97)00400-0_BIB2.1","doi-asserted-by":"crossref","unstructured":"For recent reviews on benzo-o-quinodimethanes see: a) Charlton, J.L.; Alauddin, M.M. Tetrahedron, 1987, 43, 2873\u20132889;","DOI":"10.1016\/S0040-4020(01)86825-3"},{"key":"#cr-split#-10.1016\/S0040-4039(97)00400-0_BIB2.2","doi-asserted-by":"crossref","unstructured":"b) Martin, N.; Seonae, C.; Hanack, M. Organic Prep. and Procedures Int., 1991, 23, 237\u2013272","DOI":"10.1080\/00304949109458320"},{"key":"#cr-split#-10.1016\/S0040-4039(97)00400-0_BIB3.1","unstructured":"For recent reviews on heteroaromatic o-quinodimethanes see: a) Chou, T.-S. Reviews on Heteroatom Chem., 1993, 8, 65\u2013104;"},{"key":"#cr-split#-10.1016\/S0040-4039(97)00400-0_BIB3.2","doi-asserted-by":"crossref","unstructured":"b) Ando, K.; Takayama, H. Heterocycles, 1994, 37, 1417\u20131439","DOI":"10.3987\/REV-93-SR18"},{"key":"10.1016\/S0040-4039(97)00400-0_BIB4","unstructured":"a) Fern\u00e1ndez-Paniagua, U.M.; Illescas, B.M.; Mart\u00edn, N.; Seoane, C. J. Chem. Soc., Perkin Trans. 1, 1996, 1077\u20131079; b) Eguchi, S.; Ohno, M.; Kojima, S.; Koide, N.; Yashiro, A.; Shirakawa, Y.; Ishida, H. Fullerene Sci. Technol., 1996, 4, 303\u2013327."},{"key":"10.1016\/S0040-4039(97)00400-0_BIB5","doi-asserted-by":"crossref","unstructured":"a) Tom\u00e9, A.C.; Cavaleiro, J.A.S.; Storr, R.C. Tetrahedron, 1996, 52, 1735\u20131746; b) Tom\u00e9, A.C.; Cavaleiro, J.A.S.; Storr, R.C. Tetrahedron Lett., 1993, 34, 6639\u20136642","DOI":"10.1016\/0040-4039(93)88125-3"},{"key":"10.1016\/S0040-4039(97)00400-0_BIB6","doi-asserted-by":"crossref","unstructured":"a) Tom\u00e9, A.C.; Cavaleiro, J.A.S.; Storr, R.C. Tetrahedron, 1996, 52, 1723\u20131734; b) Tom\u00e9, A.C.; O'Neill, P.M.; Cavaleiro, J.A.S.; Storr, R.C. Synlett, 1993, 347\u2013348","DOI":"10.1055\/s-1993-22450"},{"key":"10.1016\/S0040-4039(97)00400-0_BIB7","unstructured":"Typical procedure: C60 (72 mg; 0.1 mmol) and pyrimidine 5a (28 mg; 0.1 mmol) were heated in refluxing 1,2,4-trichlorobenzene (5ml), under nitrogen atmosphere, for 3 hours. After cooling to room temperature, the mixture was applied to the top of a column of silica; the trichlorobenzene and the unreacted C60 were eluted with toluene and the adduct was then eluted with chloroform."},{"key":"10.1016\/S0040-4039(97)00400-0_BIB8","unstructured":"All adducts (6a, 6b, 8a, 8b) have melting points higher than 320 \u00b0C. Adduct 6a: 1H-NMR (300 MHz, CS2\/DMSO-d6), \u03b4= 4.23 (s, 3H, OCH3), 4.66 (s, 2H, CH2), 4.77 (s, 2H, CH2), 7.38\u20137.44 (m, 3H, ArH), 8.53\u20138.53 (m, 2H, ArH); 13C-NMR (75 MHz, CS2\/DMSO), \u03b4= 36.1, 45.8, 53.4, 64.6, 64.7, 114.2, 128.0, 128.1, 190.3, 135.1, 135.2, 137.0, 139.7, 141.17, 141.21, 141.6, 141.7, 142.1, 142.6, 144.16, 144.19, 144.8, 144.9, 145.0, 145.1, 145.3, 145.7, 146.0, 147.1, 155.8, 162.2, 165.3, 166.5; MS (LSIMS; NBA) [M + H] = 933, [C60] = 720"},{"key":"10.1016\/S0040-4039(97)00400-0_BIB9","unstructured":"Sulfone 5b was obtained by the procedure described in [5]. M.p. = 255\u2013226 \u00b0C; 1H-NMR (300 MHz, CDCl3), \u03b4= 3.0 (t, 4H), 3.67 (t, 4H), 4.36 (s, 2H), 4.38 (s, 2H), 7.45\u20137.48 (m, 3H), 8.32\u20138.35 (m, 2H); 13C-NMR (75 MHz, CDCl3), \u03b4= 46.0, 47.6, 56.6, 57.0, 106.2, 128.1, 128.4, 130.9, 137.2, 160.0, 160.3, 163.5; MS (EI+) m\/z (rel.int.) 330 (M+, 4%), 262 (60), 224 (13), 211 (27), 210 (30), 198 (36), 181 (18), 104 (100), 85 (19), 77 (35), 69 (29)"},{"key":"10.1016\/S0040-4039(97)00400-0_BIB10","unstructured":"The 13C-NMR spectrum of compound 6c shows nine signals corresponding to nine sp3 carbons. This means that the four carbon atoms of the piperazinyl group are not magnetically equivalent. This effect (not observed in sulfone 5b lacking the acetyl group)[9]is probably due to the restricted rotation of the acetyl group about the C-N bond (a phenomenon common to N,N'-disubstituted amides) [11]."},{"key":"10.1016\/S0040-4039(97)00400-0_BIB11","unstructured":"Stothers, J.B. \u201cCarbon-13 NMR Spectroscopy\u201d, Academic Press, New York, 1972, pag. 427"},{"key":"10.1016\/S0040-4039(97)00400-0_BIB12","unstructured":"In the reaction of C60 with 7b the adduct 8b was accompaigned by a minor fraction corresponding to 2:1 adducts (two pyrimodone o-quinodimethanes added to one fullerene molecule), as indicated by its mass spectrum."},{"key":"10.1016\/S0040-4039(97)00400-0_BIB13","unstructured":"Adduct 8b: 1H-NMR (300 MHz, CS2\/CDCl3), d= 2.72 (s, 3H), 3.72 (s, 3H), 4.47 (s, 2H), 4.51 (s, 2H); 13C-NMR (75 MHz, CS2\/CDCl3), \u03b4= 23.4, 31.3, 36.8, 45.9, 64.88, 64.91, 119.0, 135.1, 135.4, 139.9, 140.0, 141.40, 141.44, 141.8, 141.9, 142.3, 142.9, 144.3, 144.5, 144.8, 145.1, 145.2, 145.3, 145.5, 146.0, 146.2, 146.3, 147.3, 147.4, 155.6, 155.8, 158.4, 160.0, 160.7; MS (LSIMS; NBA) [M + H] = 871, [C60] = 720; IR \u03bdmax (KBr) 2360, 2341, 1666, 1540, 1428, 669, 526"},{"key":"10.1016\/S0040-4039(97)00400-0_BIB14","doi-asserted-by":"crossref","first-page":"2143","DOI":"10.1246\/bcsj.69.2143","volume":"69","author":"Nakamura","year":"1996","journal-title":"Bull. Chem. Soc. Japan"}],"container-title":["Tetrahedron Letters"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.elsevier.com\/content\/article\/PII:S0040403997004000?httpAccept=text\/xml","content-type":"text\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/api.elsevier.com\/content\/article\/PII:S0040403997004000?httpAccept=text\/plain","content-type":"text\/plain","content-version":"vor","intended-application":"text-mining"}],"deposited":{"date-parts":[[2020,1,7]],"date-time":"2020-01-07T20:56:09Z","timestamp":1578430569000},"score":1,"resource":{"primary":{"URL":"https:\/\/linkinghub.elsevier.com\/retrieve\/pii\/S0040403997004000"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1997,4]]},"references-count":16,"journal-issue":{"issue":"14","published-print":{"date-parts":[[1997,4]]}},"alternative-id":["S0040403997004000"],"URL":"https:\/\/doi.org\/10.1016\/s0040-4039(97)00400-0","relation":{},"ISSN":["0040-4039"],"issn-type":[{"value":"0040-4039","type":"print"}],"subject":[],"published":{"date-parts":[[1997,4]]}}}