Chinazolincarbonsäuren. VII. Mitteilung. Ein einfacher Zugang zu (4-Oxo-3,4-dihydrochinazolin-3-yl)-alkansäuren, (4-Oxo-3,4-dihydro-1,2,3-benzotriazin-3-yl)-alkansäuren und deren Estern

✍ Scribed by Manfred Süsse; Siegfried Johne

• Publisher: John Wiley and Sons
• Year: 1985
• Tongue: German
• Weight: 529 KB
• Volume: 68
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.19850680410

✦ Synopsis

Quinazoline Carboxylic Acids. An Easy Route to (4‐Oxo‐3,4‐dihydroquinazolin‐3‐yl)‐alkanoic Acids, (4‐Oxo‐3,4‐dihydro‐1,2,3‐benzotriazin‐3‐yl)‐alkanoic Acids and their Esters

A new route was found for the synthesis of (4‐Oxo‐3,4‐dihydroquinazolin‐3‐yl)‐alkanoic acids (8) and (4‐Oxo‐3,4‐dihydro‐1,2,3‐benzotriazin‐3‐yl)‐alkanoic acids (6) by cyclization of the N‐(2‐aminobenzoyl)amino acids 5 with HCOOH or HNO~2~. 2__H__‐3,1‐Benzoxazine‐2,4(1__H__)‐diones (1) reacted with glycine esters to 2, which were cyclized by HNO~2~ to the esters 4. Ester 4 was hydrolyzed to 6 (X = CH~2~). Diones 1 reacted with the most common amino acids (as the ammonium salt of tertiary amine) to amino‐alkanoic acids 5, which were cyclized with orthoformate to 7 or 8 depending on the reaction conditions.