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Updated: Dec 11, 2025

Facile Preparation of 4-Substituted Quinazoline Derivatives
Published on: February 15, 2016
Ring Enlargement of N-Phosphanyl-1,2,3,4-tetrahydroquinazolines
Anatoliy Marchenko1, Georgyi Koidan1, Anastasiia N Hurieva1
1Institute of Organic Chemistry, National Academy of Sciences of Ukraine, Murmanska 5, Kyiv 94 02660, Ukraine.
Abstract:
We found that 1-phosphanyl-1,2,3,4-tetrahydroquinazolines undergo ring enlargement. Their treatment with trifluoroacetic or hydrochloric acid afforded diazaphosphepinium salts. Deprotonation of these salts gave the corresponding neutral diazaphosphepines. The reaction of 1-phosphanyl-1,2,3,4-tetrahydroquinazolines with diazomethane or phenylazide afforded triazaphosphocine derivatives via insertion of P-N moiety. At the same time, an analogous hexahydropyrimidine derivative reacted with phenylazide in a normal manner at the phosphorus atom to afford the P(V) derivative.
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