N-(Aminophenyl)oxamic acids and esters as potent, orally active antiallergy agents

Abstract

dichloromethane (25 mL). The tan solid was filtered off and suspended in cold (0 °C) DMF (50 mL). Anhydrous ammonia was bubbled through for 10 min, and the resulting solution was allowed to stand at room temperature overnight. The DMF solution was evaporated to dryness under reduced pressure, and the residue was washed with CH2C12 and ether and dried: yield 3.0 g; mp 340-345 °C dec. Method M.7-Chloro-4,9-dihydro-4-methyl-9-oxopyrazolo[5,l-h]quinazoline-2-carbonitrile. 7-Chloro-4,9-dihydro-4-methyl-9-oxopyrazolo[5,l-6]quinazoline-2-carboxamide (3 g, 0.011 mol) was heated at 56 °C with thionyl chloride (1.6 mL, 0.022 mol) and DMF (35 mL) for 18 h. The resulting clear solution was evaporated to dryness, and the residue was treated with water (600 mL). After the solution was left standing for 1 h, the crude nitrile was filtered off, washed with water, and recrystallized from a DMF-EtOH mixture: yield 2.4 g (84%);

On the Synthesis of 2-Amino-4,6-difluorobenzonitrile: Highly Selective Formation of 5-Fluoro-3-nitro-1,2-benzoquinone 2-Diazide in the Attempted Sandmeyer Cyanation of 2,4-Difluoro-6-nitrobenzenediazonium Cation†

“…3,5 Aminobenzonitrile 4 could be obtained by the reaction of 2,4,6-tri¯uorobenzonitrile with an ethanolic solution of ammonia at room temperature following a modi®cation of the method described for the preparation of 2-amino-6-¯uorobenzonitrile. 6 In this reaction, a mixture of the two possible monosubstitution products 4 and 5 in a ratio close to the statistical one was obtained. This mixture was easily separated by column chromatography, isolating both products in 60 and 37% yield, respectively.…”

“…(500 MHz, CD 3 COCD 3 ) 6.21 (br s, 2 H, NH 2 ),6.38 (ddd, J 10.2, J' 9.5, J0 2.5 Hz, 1 H, 5-H), 6.48 (ddd, J 11.0, J' 2.5 J0 2.0 Hz, 1 H, 3-H); C (75.4 MHz, CD 3 COCD 3 ) 82.5 (C, d, J 19.5 Hz, C-1), 92.8 (CH, dd, J 24.4, J' 24.3 Hz, C-5), 98.0 (CH, d, J 26.1 Hz, C-3), 112.9 (C, CN), 154.8 (C, dd, J 6.0, J' 6.1 Hz, C-2), 165.6 (C, dd, J 252.6, J' 17.0 Hz, C-6), 167.2 (C, dd, J 250.3, J' 16.1 C-4) (Found: C, 54.57; H, 2.67; N, 18.01%. C 7 H 4 F 2 N 2 requires: C, 54.45; H, 2.62; N, 18.18%).…”

Crystal structure of 2-(bis(4-methoxyphenyl)amino)-2-oxoacetic acid, C16H15NO5

“…Aryl oxamic acid derivatives have various interesting applications [4][5][6][7][8]. In addition, aryl oxamic acids can be used as intermediates for the synthesis of various classes of compounds including heterocycles [9][10][11][12].…”

Ultrasound Promoted Oxamate Synthesis: A Chemoselective and Direct Approach from Amines

“…In the same way the oxalyl (1, 2‐dicarbonyl) group is one of the significant functionality in several biologically active species. Organic molecules with oxamate groups exhibit significant activity such as antimalarial, antiallergy, and most notably anticancer as it is a metabolic inhibitor of LDH . In prior studies, oxamates have been shown to prevent the growth and metastasis of breast, cervical, and liver cancer cells in vitro studies .…”