Pyrrolo 2,l-b quinazolines

N-3 of the quinazoline derivative was not blocked, a mixture of the angular pyrrolo[l, 2-a]quinazoline and the linear pyrrolo[2,l-b]quinazoline was ob-... 

Oxidation of the 1-aminoquinazolinones (44) with lead tetraacetate culminated in the intramolecular addition of the resulting N-nitrene intermediate to the triple bond to give the pyrrolo[2, l-b]quinazoline (45) [85CC544 86JCS(P1)1215]. The pyrrole ring of 47 was also formed by cyclization of 2-methyl-3-phenacylquinazolin-4-one (46) with dilute aqueous alkali followed by fusion (86T4481). 

Pyrrolo[2, l-b]quinazolines (49) were obtained through the formation of their diazine ring by condensation of an anthranilic acid derivative with a pyrrole derivative such as O-alkylbutyrolactimes (48) [60GEPI088968 ... 

An alternative protocol towards pyrazino 2,l-b]quinazolines 79 relied on cyclocondensation of diketopiperazine-derived lactim ethers with anthranilic acid. Microwave dielectric heating in a domestic oven (600 W irradiation power) furnished heterocycles 79 within 3-5 min, while the corresponding reaction in an oil-bath required 2 hours heating at 120-140 °C [129]. The use of N-protected co-amino acids 83 in the microwave-assisted reaction with anthranilic acid 71 furnished pyrrolo 2, -b]quinazolines 85 via transannu-lar cyclization of the intermediate cyclic diamide 84 [126]. Subsequent in situ condensation with a variety of aldehydes furnished isaindigotone 86 and analogues, possessing cytotoxic activity (Scheme 51). 

H-pyrrolo[l,2-a]imidazoles pyrrolo[3,4-b]indoles pyrrolo[2,3-b]pyridines py rrolo [1,2- a] quinoxalines quinazolines... 

Nitrogen Heterocycles.- Reactions of iminophosphoranes have been used to prepare a wide range of heterocycles. Examples of compounds prepared by intramolecular aza-Wittig reactions include 3,4-dihydroquinazolines (191) and quinazolines (192), quinazoline derivatives (e.g. 193),pyrrolo( 1,2-a)quinoxalines (194), indolo[3,2-clquinolines (195), and indolo[l,2-c]quinazolines (196),"8 imidazolinones (197),"9 quinazolinones (198),"9, 120 pyrido[2,3-d]pyrimidine derivatives (199), 21 and 4,5-dihydropyrazolo(3,4-d]pyrimidine derivatives (200). 22 Tributyl(cyclohepta-1,3,5-trienylimino)phosphorane (201), prepared by thermal isomerization of the 2,4,6-derivative, reacts with a,p-unsaturated ketones to give 9H-cyclohepta[b]pyridine derivatives (202). 23 a synthesis of (2,4)pyridinophanes (204) by the reaction of N-vinyliminophosphoranes (203) with a,P-unsaturated ketones has been reported. 24... 

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