4-Oxo-4H-1-benzopyran-2-carboxylic acid

4-Oxo-4H-1-benzopyran-2-carboxylic acid Property

Melting point:

260 °C (dec.)(lit.)

Boiling point:

285.64°C (rough estimate)

Density 

1.3366 (rough estimate)

refractive index 

1.5280 (estimate)

storage temp. 

Sealed in dry,Room Temperature

solubility 

alcohol: soluble

form 

Powder

pka

2.28±0.20(Predicted)

color 

White to beige

Water Solubility 

sparingly soluble

Merck 

14,2237

BRN 

146442

InChI

InChI=1S/C10H6O4/c11-7-5-9(10(12)13)14-8-4-2-1-3-6(7)8/h1-5H,(H,12,13)

InChIKey

RVMGXWBCQGAWBR-UHFFFAOYSA-N

SMILES

C1(C(O)=O)OC2=CC=CC=C2C(=O)C=1

CAS DataBase Reference

4940-39-0(CAS DataBase Reference)

Safety

Hazard Codes 

Xi

Risk Statements 

36/37/38

Safety Statements 

26-36-37/39

WGK Germany 

3

RTECS 

DJ2476000

Hazard Note 

Irritant

HS Code 

29329990

Toxicity

LD50 intraperitoneal in mouse: 585mg/kg

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H315Causes skin irritation

H319Causes serious eye irritation

H335May cause respiratory irritation

Precautionary statements

P261Avoid breathing dust/fume/gas/mist/vapours/spray.

P264Wash hands thoroughly after handling.

P264Wash skin thouroughly after handling.

P271Use only outdoors or in a well-ventilated area.

P280Wear protective gloves/protective clothing/eye protection/face protection.

P302+P352IF ON SKIN: wash with plenty of soap and water.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

4-Oxo-4H-1-benzopyran-2-carboxylic acid Chemical Properties,Usage,Production

Chemical Properties

white to light yellow crystal powder

Uses

vascular protectant

Uses

Chromone-2-carboxylic acid is used in the cyclic form 3?-oxopyrazolidino[4?,5??2, 3]-chroman-4-one, gives the azide of chromone-2-carboxylic acid, the curtius rearrangement of which is used to synthesize a number of 2-acylaminochromones and it is an orally active antiallergic agent.

Uses

4-oxo-4H-1-Benzopyran-2-carboxylic Acid acts as an inhibitor of monoamine oxidase A & B. Also functions as a novel type of tyrosine phosphatase 1B inhibitor in studies, due to a structure derived from formylchromone.

Definition

ChEBI: 4-oxo-1-benzopyran-2-carboxylic acid is a member of chromones.

General Description

Nasal absorption of 4-oxo-4H-1-benzopyran-2-carboxylic acid has been investigated in the male Wistar rat.

Synthesis

Example 8 Synthesis of 4-oxo-4H-chromene-2-carboxylic acid Procedure: a mixture of diethyl oxalate (110 mL, 810 mmol) and 2'-hydroxyacetophenone (44 mL, 365 mmol) was added slowly and dropwise to a solution of sodium ethanolate (76 g, 1.11 mol) in ethanol (600 mL) over a period of 20 minutes. The reaction mixture was heated to 80 °C and maintained for 1 h, followed by cooling to room temperature. Water (500 mL) and ether (600 mL) were added to the reaction system and the pH was adjusted with concentrated hydrochloric acid to 2. The organic phase was separated and the aqueous phase was further extracted with ether (2 x 600 mL). The organic phases were combined, washed with saturated aqueous sodium chloride solution (2 x 600 mL), dried over anhydrous magnesium sulfate and concentrated to give a brown oily solid. The solid was mixed with glacial acetic acid (440 mL) and concentrated hydrochloric acid (110 mL) and heated to 85 °C for overnight reaction. After the reaction was completed, it was cooled to room temperature, diluted with water (550 mL) and the solid was collected by filtration. The solid was washed with water (2 x 125 mL) and dried in a vacuum oven to give a purple solid product (58 g, 83% yield). Melting point: 260-261 °C. 1H NMR (300 MHz, DMSO-d6) δ 8.03 (m, 1H), 7.85 (m, 1H), 7.71 (m, 1H), 7.51 (m, 1H), 6.89 (s, 1H).

References

[1] Patent: US6469031, 2002, B1
[2] Patent: US6051586, 2000, A
[3] Zhurnal Obshchei Khimii, 1959, vol. 29, p. 1026,1029; engl. Ausg. S. 1004, 1006
[4] Helvetica Chimica Acta, 1951, vol. 34, p. 767,774
[5] Chimica Therapeutica, 1968, vol. 3, p. 270 - 273