4-Quinazolone-2-carboxylic

Quinazolone-2-carboxylic acid esters from o-aminocarboxylic acid amides... 

Most cyclizations of 2,3-diaminopyrimidones (e.g., 68) (04JAP(K)107228) or corresponding quinazolones proceed with the participation of carboxylic acids or their derivatives (esters, anhydrides, chlorides, or orthoesters) as shown in Scheme 18. 

IA and O-substituted hydroxylamines (131) give anthranilic acid hydrox-ylamides (132)96 (hydroxylamine itself forms the O-acyl derivative95). Carboxylic acids and anhydrides cyclize 132 to the quinazolones 13396 (Eq. 14). 

IA with aliphatic and aromatic carboxylic amides (150 X = O) gives the quinazolones 151187 191 (Eq. 16). Lactams similarly yield C-2-N-3 bridged quinazolones182,192 196 [e.g., the natural products courupitine A 152196 and... 

Carboxylic acid chlorides add in a like manner to carbodiimides to form the corresponding 1 1 adducts, which have a chloroformamidine structure. For example, acetyl chloride was added to carbodiimides, and the structure of the labile 1 1 adducts (XXVII) was established by subsequent reactions with anthranilamide, leading to 4-quinazolones XXVIII... 

Compounds tested and found active in vitro against M. tuberculosis include 5-arylamino-3-pheny1thiazolidin-2,4-diones 2,3-diaryl-5-arylazo-4-thiazolidinethione-1,1-dioxides N-substituted benzisothia-zolin-3-thiones 5 4-(indol-3-yl)-imidazoles , indol-3-ylcarboxylic acids and hydrazides 3-halophenylazoindoles , 3,4-dihydropyrido[2,3-d]pyri-dazin-1[2H]-one 5, Schiff bases from isoniazid and substituted benzalde-hydes °, 5-n-butylpyridine-2-carboxylic acid hydrazide, 4-thiosemicar-bazido-2-[(5-nitrofuryl)vinyl]quinolones and butadiene analogs3-thio-4 3H)quinazolone derivatives, and N- ji-tolyl)-N -(2-benzothiazolyl)-N "-alkylquanidines. ... 

In addition, 2,3-disubstituted-4-quinazolones (29) can be synthesized from A-acylanthranilic acids by treating 27 with various amines. Generally, addition of the amine is carried out in the presence of an agent to activate the carboxylic acid, such as phosphorous trichloride (PCb) or 1,1 -carbonyldiimidazole (CDI). ... 

A one-pot, two-step microwave assisted method to prepare 2,3-disubstituted 4-quinazolones was developed by Lui et al and was subsequently used for the synthesis of several natural products. By this method, heating 59 and either a carboxylic acid or an acid chloride in the presence of triphenyl phosphite in pyridine followed by addition of an amine produced 61 via acylanthranil 60 in generally good yield. The reaction produced a lower yield of 61 when the reaction mixture was heated at 120 under conventional heating conditions, providing < 50% conversion of cyclized product 61 along with multiple side products. 

Quinazoline methiodide, 29 Quinazoline 3-oxides, 31 Quinazoline-thiones, 31, 51 4-Quinazolone, 3-alkyl-, 31 Quindolines, 103, 134, 144, 146 Quindoline-11-carboxylic acid, 144 Quinindoline, 135, 144 Quinolines, alkoxy-, reactions of, 311 2-alkyl-, reaction with carbenes, 77 aza-effects in, 318 basicity of, 244, 245, 247, 288, 289... 

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