Synthese von 8H‐Phthalazino[1.2‐b]chinazolonen‐(8)

Abstract

Synthese yon SH-Phthalazino[ 1.2-b]chinazolonen-(S)Aus dem Institut fur Organische Chemie der Universitat Greifswald

Preparation of pyrimido[2,1-a]phthalazines and an aminopyrimido[2,1-a]isoindole by retro Diels–Alder reaction

“…Other aromatic analogues of types 6 and 7 were synthesized earlier by the cyclocondensation of anthranilic acid with 1-chlorophthalazines. 12 The pyrimido[2,1-a]phthalazine ring system has also been prepared by the cyclization of hydroxyalkylaminophthalazinones. 13-16…”

“…e d, J: 8.5 (9a,b), 7.7 ± 0.2 (11, 18, 20, 21), 7.3 (13), 6.4 (14, 19), dd, J: 11.7 (6a,b, 16) or 9.5 (8a,b, 10) and 3.5 (6a, 16), 4.7 (6b) or 4.0 (8a,b, 10). f d, J: 8.8 (7a), see at 4a-H (9b, 13, 14, 19, 20, 21), dd, J: 9 and 3 (7b), 8.3 and 2.7 (9a), 11.8 and 3.7 (16), 11.8 and 7.5 (18, the split of 7.5 is due to CH,NH-coupling), td, J: 11.6, 3.3 and 3.3 (6a,b); 9.6, 3.4 and 3.4 (8a,b), dt, J: 10.1, 10.1 and 3.8(10), unresolved triplet-like signal(12). g Coalesced m, half signal width: 8 (6a, 8a, 9a,b and 14), 12 (8b), ~25(10), doublet-like signal with coalesced fine-structure (6b), dd, J: 9.0 and 4.0 (12), 12.1 and 3.8(13), dt, J: 12.3, 12.3 and 2.5(20,21).…”

“…g Coalesced m, half signal width: 8 (6a, 8a, 9a,b and 14), 12 (8b), ~25(10), doublet-like signal with coalesced fine-structure (6b), dd, J: 9.0 and 4.0 (12), 12.1 and 3.8(13), dt, J: 12.3, 12.3 and 2.5(20,21). h Triplet doublet, J: 12.4, 4.3 and 4.3 (6a, 8b), 12.9 and 4.3 (9a), with coalesced fine-structure(12,14), coalesced m, half signal width: 25 (6b, 7a,b), ~18(10), ddd, J: 12.5, 4.8 and 3.6 (8a), dt, J: 12.0, 12.0 and 2.8(20,21). i AAЈBBЈ-type spectrum, 2 × ~d (2 × 2H), J: 8.1 ± 0.2, singlet-like signal (4H) for 21. j,k Overlapping signals; l 6Ј-H(eq), m, Ar(6Ј)H, d for 16, 18, 19, J: 7.3 (16), 8.0 (18, 19).…”

The Chemistry of Hydrazonates

“…Hydrazonates 233, prepared by reaction of 3-hydrazinopyridazines with orthoesters, were reported to undergo cyclization to give the respective title compounds 234 [134][135][136][137][138].…”