Premium
A new ring transformation of 3‐halo‐2‐azidopyridine 1‐oxides. A novel synthesis of 1,2‐oxazin‐6‐ones
Author(s) -
Abramovitch Rudolph A.,
Shinkai Ichiro,
Cue Berkeley W.,
Ragan Francis A.,
Atwood Jerry L.
Publication year - 1976
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.5570130247
Subject(s) - chemistry , ring (chemistry) , halo , substituent , hydrolysis , stereochemistry , crystallography , organic chemistry , physics , quantum mechanics , galaxy
The course of the thermal ring‐opening and recyclization of 2‐azidopyridine 1‐oxides is radically altered by the presence of a 3‐halo substituent. Provided the 6‐position is blocked, recyclization leads to a 6‐cyano‐6‐halo‐1,2‐oxazine which hydrolyzes very readily to the 6 H ‐1,2‐oxazin‐6‐one. The structure of 4‐bromo‐3‐methyl‐6 H ‐1,2‐oxazin‐6‐one so obtained was confirmed by single crystal X‐ray analysis. If the 6‐position is not blocked, the product undergoes a further ring opening to give ( Z )‐β‐cyanoacrylates.