{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T04:41:09Z","timestamp":1760244069041,"version":"build-2065373602"},"reference-count":29,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2007,3,21]],"date-time":"2007-03-21T00:00:00Z","timestamp":1174435200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>Liquid-liquid phase transfer alkylation of 4-methoxy-pyrazolo[3,4-d]-pyrimidine (1a) with a dichloromethane\/dibromomethane mixture (3:1, v\/v) gave the regioisomeric methylenebis(heterocycles) 3a\u20135a. These were converted by dilute aqueous sodium hydroxide containing dimethylsulfoxide (DMSO) at concentrations between 0 and 60 vol-% into the methylenebis(allopurinols) 3b\u20135b by nucleophilic SNAr reactions at C(4). The effect of DMSO on the reaction kinetics was investigated.<\/jats:p>","DOI":"10.3390\/12030563","type":"journal-article","created":{"date-parts":[[2008,10,25]],"date-time":"2008-10-25T13:32:11Z","timestamp":1224941531000},"page":"563-575","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Symmetrically and Unsymmetrically Bridged Methylenebis(allopurinols): Synthesis of Dimeric Potential Anti-Gout Drugs"],"prefix":"10.3390","volume":"12","author":[{"given":"Helmut","family":"Rosemeyer","sequence":"first","affiliation":[{"name":"Organische Chemie I \u2013 Bioorganische Chemie, Institut f\u00fcr Chemie, Fachbereich Biologie\/Chemie, Universit\u00e4t Osnabr\u00fcck, Barbarastr. 7, D-49069 Osnabr\u00fcck, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Martina","family":"Anders","sequence":"additional","affiliation":[{"name":"Organische Chemie I \u2013 Bioorganische Chemie, Institut f\u00fcr Chemie, Fachbereich Biologie\/Chemie, Universit\u00e4t Osnabr\u00fcck, Barbarastr. 7, D-49069 Osnabr\u00fcck, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Frank","family":"Seela","sequence":"additional","affiliation":[{"name":"Organische Chemie I \u2013 Bioorganische Chemie, Institut f\u00fcr Chemie, Fachbereich Biologie\/Chemie, Universit\u00e4t Osnabr\u00fcck, Barbarastr. 7, D-49069 Osnabr\u00fcck, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2007,3,21]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"784","DOI":"10.1021\/ja01585a023","article-title":"Potential Purine Antagonists. 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