par Marchal, Lucien 
;Promel, Robert ;Martin, Richard ;Cardon, Anne
Référence Bulletin des Sociétés chimiques belges, 69, 3-4, page (177-193)
Publication Publié, 1960
;Promel, Robert ;Martin, Richard ;Cardon, AnneRéférence Bulletin des Sociétés chimiques belges, 69, 3-4, page (177-193)
Publication Publié, 1960
Article révisé par les pairs
| Résumé : | 5‐ammo‐4‐chloro‐6‐mercaptopyrimidine (II) is obtained from 5‐amino‐4,6‐dichloropyrimidine (I) by reaction with NaSH. When thiourea is used under similar conditions, no monosubstitution is observed. The same is true in the case of 4,6‐dichloropyrimidine. An explanation of these facts is suggested. On heating with excess ethyl orthoformate, II gives 7‐chlorothiazolo [5,4‐d] pyrimidine (III). Compounds IV to X are prepared from III by substitution of the chlorine atom with suitable nucleophilic reagents. Ammonolysis of III however failed. Catalytic dehalogenation of III to give unsubstituted thiazolo [5,4‐d] pyrimidine (XI), was also unsuccessful. An other attempt to synthesise XI, based on the desulfurisation of II to 5‐amino‐4‐chloropyrimidine (XV) is described. Treatment of II with Raney nickel gives either 5‐aminopyrimidine (XVI) alone or a mixture of XV and XVI, according to the reaction time. Finally a third scheme to prepare XI was studied. With sodium methoxide, I is converted to 5‐amino‐4‐chloro‐6‐méthoxypyrimidine (XVII) which is dehalogenated in the presence of hydrogen and Pd/C. On heating with conc. HCl, 5‐amino‐4‐methoxypyrimidine (XVIII) is demethylated to 5‐amino‐4‐hydroxypyrimidine (XIX). Attempts to chlorinate XIX have been unsuccessful. Copyright © 1960 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim |
