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Preparation of 2‐amino‐5‐methyl‐7 H ‐1,3,4‐thiadiazolo[3,2‐α]pyrimidin‐7‐ones
Author(s) -
Safarov Saifidin,
Kukaniev Muhamacho Ahmadovich,
Kolshorn Heinz,
Meier Herbert
Publication year - 2005
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570420611
Subject(s) - chemistry , heteronuclear molecule , dimethylamine , stereochemistry , chlorine atom , hydrogen atom , diketene , medicinal chemistry , nuclear magnetic resonance spectroscopy , organic chemistry , group (periodic table)
2‐Amino substituted 7 H ‐1,3,4‐thiadiazolo[3,2‐α]pyrimidin‐7‐ones 11a‐e were prepared by the reaction of 2‐bromo‐5‐amino‐1,3,4‐thiadiazole ( 1b ) and diketene ( 8 ), subsequent cyclocondensation ( 9b → 3b ) and displacement of the bromo substituents by the reaction with primary or secondary amines ( 3b → 11a‐e ). The hydrogen atom 6‐H in the heterobicycle 3b is replaced by a Cl or Br atom in the transformation of 3b → 14a,b. The 2‐bromo‐6‐chloro compound 14a reacts chemoselectively in the 2‐position with dimethylamine ( 14a → 15 ). The structure elucidations are based on one‐ and two‐dimensional NMR techniques including a heteronuclear NOE measurement.