55687-34-8|6-Bromoquinoxalin-2(1H)-one| Ambeed

Size	Price	VIP Price	US Stock	Global Stock	In Stock
{[ item.pr_size ]}		Inquiry {[ getRatePrice(item.pr_usd,item.pr_rate,item.mem_rate,item.pr_is_large_size_no_price, item.vip_usd) ]}

US Stock: ship in 0-1 business day
Global Stock: ship in 5-7 days

{[ item.pr_size ]}

In Stock

- +

Please Login or Create an Account to: See VIP prices and availability

US Stock: ship in 0-1 business day
Global Stock: ship in 2 weeks

Quality Control of [ 55687-34-8 ] Purity: 95% SDS Specification

COA

Search for reports by entering the product batch number.
Batch number can be found on the product's label following the word 'Batch'.

NMR

Search for reports by entering the product batch number.
Batch number can be found on the product's label following the word 'Batch'.

CNMR

Search for reports by entering the product batch number.
Batch number can be found on the product's label following the word 'Batch'.

HPLC

Search for reports by entering the product batch number.
Batch number can be found on the product's label following the word 'Batch'.

LC-MS

Search for reports by entering the product batch number.
Batch number can be found on the product's label following the word 'Batch'.

1-2 Day Shipping
High Quality
Technical Support

Product Details of [ 55687-34-8 ]

CAS No. :	55687-34-8
Formula :	C₈H₅BrN₂O
M.W :	225.04
SMILES Code :	BrC2=CC=C1N=C(C=NC1=C2)O
MDL No. :	MFCD09834132
InChI Key :	BDBWPIXISLYKEG-UHFFFAOYSA-N
Pubchem ID :	12686394

Safety of [ 55687-34-8 ]

GHS Pictogram:
Signal Word:	Warning
Hazard Statements:	H302-H315-H319-H332-H335
Precautionary Statements:	P261-P280-P305+P351+P338

Computational Chemistry of [ 55687-34-8 ] Show Less

Physicochemical Properties

Num. heavy atoms	12
Num. arom. heavy atoms	10
Fraction Csp3	0.0
Num. rotatable bonds	0
Num. H-bond acceptors	3.0
Num. H-bond donors	1.0
Molar Refractivity	49.26
TPSA ? Topological Polar Surface Area: Calculated from Ertl P. et al. 2000 J. Med. Chem.	46.01 Å²

Lipophilicity

Log P_o/w (iLOGP)? iLOGP: in-house physics-based method implemented from Daina A et al. 2014 J. Chem. Inf. Model.	1.87
Log P_o/w (XLOGP3)? XLOGP3: Atomistic and knowledge-based method calculated by XLOGP program, version 3.2.2, courtesy of CCBG, Shanghai Institute of Organic Chemistry	1.88
Log P_o/w (WLOGP)? WLOGP: Atomistic method implemented from Wildman SA and Crippen GM. 1999 J. Chem. Inf. Model.	2.1
Log P_o/w (MLOGP)? MLOGP: Topological method implemented from Moriguchi I. et al. 1992 Chem. Pharm. Bull. Moriguchi I. et al. 1994 Chem. Pharm. Bull. Lipinski PA. et al. 2001 Adv. Drug. Deliv. Rev.	1.4
Log P_o/w (SILICOS-IT)? SILICOS-IT: Hybrid fragmental/topological method calculated by FILTER-IT program, version 1.0.2, courtesy of SILICOS-IT, http://www.silicos-it.com	2.13
Consensus Log P_o/w? Consensus Log P_o/w: Average of all five predictions	1.88

Water Solubility

Log S (ESOL):? ESOL: Topological method implemented from Delaney JS. 2004 J. Chem. Inf. Model.	-3.04
Solubility	0.207 mg/ml ; 0.00092 mol/l
Class? Solubility class: Log S scale Insoluble < -10 < Poorly < -6 < Moderately < -4 < Soluble < -2 Very < 0 < Highly	Soluble
Log S (Ali)? Ali: Topological method implemented from Ali J. et al. 2012 J. Chem. Inf. Model.	-2.47
Solubility	0.766 mg/ml ; 0.0034 mol/l
Class? Solubility class: Log S scale Insoluble < -10 < Poorly < -6 < Moderately < -4 < Soluble < -2 Very < 0 < Highly	Soluble
Log S (SILICOS-IT)? SILICOS-IT: Fragmental method calculated by FILTER-IT program, version 1.0.2, courtesy of SILICOS-IT, http://www.silicos-it.com	-3.61
Solubility	0.0549 mg/ml ; 0.000244 mol/l
Class? Solubility class: Log S scale Insoluble < -10 < Poorly < -6 < Moderately < -4 < Soluble < -2 Very < 0 < Highly	Soluble

Pharmacokinetics

GI absorption? Gatrointestinal absorption: according to the white of the BOILED-Egg	High
BBB permeant? BBB permeation: according to the yolk of the BOILED-Egg	Yes
P-gp substrate? P-glycoprotein substrate: SVM model built on 1033 molecules (training set) and tested on 415 molecules (test set) 10-fold CV: ACC=0.72 / AUC=0.77 External: ACC=0.88 / AUC=0.94	No
CYP1A2 inhibitor? Cytochrome P450 1A2 inhibitor: SVM model built on 9145 molecules (training set) and tested on 3000 molecules (test set) 10-fold CV: ACC=0.83 / AUC=0.90 External: ACC=0.84 / AUC=0.91	Yes
CYP2C19 inhibitor? Cytochrome P450 2C19 inhibitor: SVM model built on 9272 molecules (training set) and tested on 3000 molecules (test set) 10-fold CV: ACC=0.80 / AUC=0.86 External: ACC=0.80 / AUC=0.87	No
CYP2C9 inhibitor? Cytochrome P450 2C9 inhibitor: SVM model built on 5940 molecules (training set) and tested on 2075 molecules (test set) 10-fold CV: ACC=0.78 / AUC=0.85 External: ACC=0.71 / AUC=0.81	No
CYP2D6 inhibitor? Cytochrome P450 2D6 inhibitor: SVM model built on 3664 molecules (training set) and tested on 1068 molecules (test set) 10-fold CV: ACC=0.79 / AUC=0.85 External: ACC=0.81 / AUC=0.87	No
CYP3A4 inhibitor? Cytochrome P450 3A4 inhibitor: SVM model built on 7518 molecules (training set) and tested on 2579 molecules (test set) 10-fold CV: ACC=0.77 / AUC=0.85 External: ACC=0.78 / AUC=0.86	No
Log Kp (skin permeation)? Skin permeation: QSPR model implemented from Potts RO and Guy RH. 1992 Pharm. Res.	-6.34 cm/s

Druglikeness

Lipinski? Lipinski (Pfizer) filter: implemented from Lipinski CA. et al. 2001 Adv. Drug Deliv. Rev. MW ≤ 500 MLOGP ≤ 4.15 N or O ≤ 10 NH or OH ≤ 5	0.0
Ghose? Ghose filter: implemented from Ghose AK. et al. 1999 J. Comb. Chem. 160 ≤ MW ≤ 480 -0.4 ≤ WLOGP ≤ 5.6 40 ≤ MR ≤ 130 20 ≤ atoms ≤ 70	None
Veber? Veber (GSK) filter: implemented from Veber DF. et al. 2002 J. Med. Chem. Rotatable bonds ≤ 10 TPSA ≤ 140	0.0
Egan? Egan (Pharmacia) filter: implemented from Egan WJ. et al. 2000 J. Med. Chem. WLOGP ≤ 5.88 TPSA ≤ 131.6	0.0
Muegge? Muegge (Bayer) filter: implemented from Muegge I. et al. 2001 J. Med. Chem. 200 ≤ MW ≤ 600 -2 ≤ XLOGP ≤ 5 TPSA ≤ 150 Num. rings ≤ 7 Num. carbon > 4 Num. heteroatoms > 1 Num. rotatable bonds ≤ 15 H-bond acc. ≤ 10 H-bond don. ≤ 5	0.0
Bioavailability Score? Abbott Bioavailability Score: Probability of F > 10% in rat implemented from Martin YC. 2005 J. Med. Chem.	0.55

Medicinal Chemistry

PAINS? Pan Assay Interference Structures: implemented from Baell JB. & Holloway GA. 2010 J. Med. Chem.	0.0 alert
Brenk? Structural Alert: implemented from Brenk R. et al. 2008 ChemMedChem	0.0 alert: heavy_metal
Leadlikeness? Leadlikeness: implemented from Teague SJ. 1999 Angew. Chem. Int. Ed. 250 ≤ MW ≤ 350 XLOGP ≤ 3.5 Num. rotatable bonds ≤ 7	No; 1 violation:MW<1.0
Synthetic accessibility? Synthetic accessibility score: from 1 (very easy) to 10 (very difficult) based on 1024 fragmental contributions (FP2) modulated by size and complexity penaties, trained on 12'782'590 molecules and tested on 40 external molecules (r² = 0.94)	1.98

Application In Synthesis of [ 55687-34-8 ]

* All experimental methods are cited from the reference, please refer to the original source for details. We do not guarantee the accuracy of the content in the reference.

Downstream synthetic route of [ 55687-34-8 ]

[ 55687-34-8 ] Synthesis Path-Downstream 1~35

1
[ 55687-34-8 ]
[ 55687-02-0 ]

Yield	Reaction Conditions	Operation in experiment
87%	With trichlorophosphate; at 60℃;	[001023] Part C. Preparation of 6-bromo-2-chloroquinoxaline.; [001024] To a flask containing phosphorus oxychloride (3.4ml, 36.5mmol) was added the product fromPart B (255mg, l.lmmol) and the solution was heated at 6O0C overnight. The solution was cooled to room temperature, poured over ice and the resulting solid collected by filtration to give the title compound (239mg, 87%).
70%	With N,N-dimethyl-aniline; trichlorophosphate; at 15℃; for 0.25h;Reflux;	Compound 39 (600 mg, 2.66 mmol) was added to cold phosphorous oxychloride (4 mL) in portions wise to give a slurry. To the resulting slurry was added drop wise N,N- dimethylaniline (0.4 ml, 2.93 mmol) below 15C. The brick red mixture was refluxed for 15 min, and the resulting dark brown clear solution was then cooled to ambient temperature. It was added to ice cold water (40 mL) , and the mixture was basified slowly with 40% aq. NaOH to pH 8. The solid was collected by filtration, washed with water (2x10 mL) and dried to give the title compound 40 (70%) .
51%	With trichlorophosphate; In N,N-dimethyl-formamide; at 50℃; for 2h;	6-bromoquinoxalin-2(1 H)-one (9.0 g, 40 mmol) was dissolved in POCI3 (50 mL) and DMF (2 mL) was added at RT. The mixture was heated at 50C for 2 hours. After completion of the reaction it was cooled to RT and was poured slowly into ice cold water. The mixture was stirred for 30 minutes and then filtered to afford crude product.The crude product was purified by column chromatography using neutral silica gel of 60- 120 mesh size. A gradient of 8-9 % DCM in hexane was used to elute the title compound (5.O g, 51%).1H NMR (d6-DMSO) D 9.03 (s, 1 H), 8.42 (d, 1H), 8.08 (dd, 1 H), 7.98 (d, 1H).

With trichlorophosphate; In N,N-dimethyl-formamide; at 120℃; for 1.5h;Product distribution / selectivity;

To a stirred solution of the compound obtained from Preparation 29 (2 g, 8.89 mmol) in phosphorus oxychloride (15 mL), was added DMF (1 mL). The mixture was stirred at 120C for 1.5 hours then allowed to cool to room temperature. The dark solution was concentrated in vacuo and cautiously quenched with crushed ice. The aqueous suspension was neutralised with 10% potassium carbonate solution and extracted with DCM (2 x 30 mL). The combined organic phases were dried (Na2SO4), filtered and concentrated to give 1.94 g of the title compound as a brown solid.1H-NMR (400 MHz, DMSOd6): delta= 9.02(1 H, s), 8.40(1 H, d), 8.06(1 H, dd), 7.98(1 H, d). LCMS (run time = 2min): R4 = 1.69 min; m/z 243; 245 [M+H]+

References: [1]ChemMedChem,2014,vol. 9,p. 1378 - 1386.
[2]Patent: WO2009/39134,2009,A1 .Location in patent: Page/Page column 185.
[3]Patent: WO2016/199943,2016,A1 .Location in patent: Page/Page column 0288.
[4]Patent: WO2010/136755,2010,A1 .Location in patent: Page/Page column 46; 47.
[5]Journal of the American Chemical Society,1949,vol. 71,p. 6,7.
[6]Journal of Medicinal Chemistry,1981,vol. 24,p. 93 - 101.
[7]Heterocycles,1985,vol. 23,p. 2025 - 2034.
[8]Patent: WO2011/4276,2011,A1 .Location in patent: Page/Page column 106.
[9]Patent: DE2433397,1974, .

2
[ 1196-57-2 ]
[ 55687-34-8 ]

Yield	Reaction Conditions	Operation in experiment
40%	With bromine; silver sulfate; In tetrachloromethane; sulfuric acid; at 20 - 50℃;	The quinoxalin-2(1H)-one (14.6 g, 0.1 mol, Aldrich, cat. no. 260517) and silver sulphate (15.6 g, 0.05 mol) were dissolved in cone. Sulfuric acid (100 ml) at 200C. Bromine (5.2 ml, 0.1 mol) was added and the reaction mixture was stirred vigorously for 24 hours. The reaction mass was then diluted with carbon tetrachloride (100 ml_), and this was heated at 5O0C. The reaction mass was then filtered and the filtrate was poured into ice cold water and stirred for 30 minutes to obtain a precipitate. The precipitate was filtered and the solid material was dried in vacuo to afford the title product (9.0 g, 40%).
	With bromine; silver sulfate; In sulfuric acid; at 20℃;Inert atmosphere;Product distribution / selectivity;	Quinoxalin-2(1H)-one (5 g, 34.2 mmol) was stirred in sulphuric acid (50 ml_) and silver sulphate was added (5.3 g, 17.1 mmol). The mixture was vigorously stirred until complete dissolution, whereupon bromine (1.76 ml_, 34.2 mmol) was added dropwise. The resulting mixture was stirred at room temperature under nitrogen overnight. Carbon tetrachloride (50 ml_) was added and the mixture was heated to 500C for 30 minutes, then filtered. The solid was washed with carbon tetrachloride and the filtrate was collected. This was poured into a beaker of crushed ice and slurried to give a thick off-white suspension. The crude material was filtered and the resulting solid was triturated in methanol and re-filtered. The solid pulled dry to give 5.44 g of the title compound as a pale brown solid.1H-NMR (400 MHz, DMSOd6): delta=12.52(1 H, bs), 8.17(1 H, s), 7.94(1 H, d), 7.68(1 H, dd), 7.22(1 H, d). LCMS (run time = 6 min): R4 = 2.29 min; m/z 225; 227 [M+H]+

References: [1]ChemMedChem,2014,vol. 9,p. 1378 - 1386.
[2]Patent: WO2010/136755,2010,A1 .Location in patent: Page/Page column 46; 47.
[3]Journal of Medicinal Chemistry,1981,vol. 24,p. 93 - 101.
[4]Patent: US2007/173508,2007,A1 .Location in patent: Page/Page column 84.
[5]Patent: WO2011/4276,2011,A1 .Location in patent: Page/Page column 106.

3
[ 98416-75-2 ]
[ 55687-34-8 ]

References: [1]Heterocycles,1985,vol. 23,p. 143 - 151.

5
[ 96089-46-2 ]
[ 55687-34-8 ]

Yield	Reaction Conditions	Operation in experiment
86%		[001021] Part B. Preparation of 6-bromoquinoxalin-2(leta)-one.; [001022] To a solution of sodium hydroxide (337mg, 8.4mmol) in H2O (2.1ml) was added the product from Part A (423mg, 1.4mmol) and stirring was continued at 650C for Ih. The cooled solution was diluted with H2O (4ml) and sodium borohydride (31.9mg, 0.84mmol) was added and stirring was continued at room temperature for 1.5h. Ice was added to the solution followed by dropwise addition of6nu HCl until acidic. The resulting solid was collected by filtration, washed with H2O, and dried in a vacuum oven to give the title compound (273mg, 86%).

References: [1]Patent: WO2009/39134,2009,A1 .Location in patent: Page/Page column 185.
[2]Heterocycles,1985,vol. 23,p. 143 - 151.

6
[ 55687-34-8 ]
[ 98416-90-1 ]

References: [1]Heterocycles,1985,vol. 23,p. 2025 - 2034.

7
[ 55687-34-8 ]
6-bromo-2-piperazin-1-yl-quinoxaline [ No CAS ]

References: [1]Journal of Medicinal Chemistry,1981,vol. 24,p. 93 - 101.

8
[ 55687-34-8 ]
[ 1071605-38-3 ]

References: [1]Journal of the American Chemical Society,1949,vol. 71,p. 6,7.

9
[ 55687-34-8 ]
sulfanilic acid-(6-bromo-quinoxalin-2-ylamide) [ No CAS ]

References: [1]Journal of the American Chemical Society,1949,vol. 71,p. 6,7.

10
[ 55687-34-8 ]
<i>N</i>-acetyl-sulfanilic acid-(6-bromo-quinoxalin-2-ylamide) [ No CAS ]

References: [1]Journal of the American Chemical Society,1949,vol. 71,p. 6,7.

11
[ 105-36-2 ]
[ 55687-34-8 ]
6-bromo-1-ethoxycarbonylmethylquinoxalin-2(1H)-one [ No CAS ]
ethyl 2-(6-bromo-2,3-dioxo-3,4-dihydroquinoxalin-1(2H)-yl)acetate [ No CAS ]

Yield	Reaction Conditions	Operation in experiment
1.95 g (80%); 1.0 g (77%)	With hydrogenchloride; sodium hydride; In dimefox; acetic acid; mineral oil;	EXAMPLE 2 6-Bromo-1-ethoxycarbonylmethylquinoxaline-2,3(1H,4H)-dione Under a nitrogen atmosphere <strong>[55687-34-8]6-bromoquinoxalin-2(1H)-one</strong> (2.03 g, 9 mmol) (J.Med.Chem., 24 , (1981), 93) was dissolved in 22 ml of dry DMF and sodium hydride (0.44 g, 10.8 mmol (60% mineral oil dispersion)) was added. After stirring for 2 h, ethyl bromoacetate (1.25 ml, 11.3 mmol) was added and the mixture was stirred for 3.5 h. The reaction mixture was poured onto crushed ice and acidified (PH = 4.5) by addition of dilute hydrochloric acid. The precipitate was filtered off, washed with water and air dried. The crude product (containing a minor fraction of O-alkylated product) was triturated with ether (100 ml), the precipitate filtered off, washed with ether and dried to afford 1.95 g (80%) of pure 6-bromo-1-ethoxycarbonylmethylquinoxalin-2(1H)-one. 1-NMR (DMSO-d6: delta 1.22 (t, 3H), 4.17 (q, 2H), 5.08 (s, 2H), 7.56 (d, 1H), 7.83 (dd, 1H), 8.09 (dd, 1H), 8.37 (s, 1H). The above ester (1.25 g; 4 mmol) was reacted with 30% H226 ml) in glacial acetic acid (16 ml) at 55C for 2 h. The mixture was cooled, the precipitate filtered off and recrystallized from dilute acetic acid to afford 1.0 g (77%) of the title compound . M.p. 282-83C. 1-NMR (DMSO-d6: delta 1.22 (t, 3H), 4.17 (q, 2H), 4.92 (s, 1H), 7.33 (m, 3H), 12.24 (br.s, 1H).

References: [1]Patent: EP520024,1996,B1 .

12
[ 108-23-6 ]
[ 55687-34-8 ]
[ 305790-88-9 ]
[ 305790-72-1 ]

Yield	Reaction Conditions	Operation in experiment
97%	In pyridine; toluene;	EXAMPLE 29 Isopropyl 7-(3-chlorophenyl)-3-oxo-3,4-dihydroquinoxalin-1(2H)-carboxylate To a solution of <strong>[55687-34-8]7-bromo-3-oxo-3,4-dihydroquinoxaline</strong> (6.8 g, 30 mmol) in pyridine (50 ml) was added a solution of isopropyl chloroformate in toluene (35 ml, 1M, 35 mmol) over 30 minutes. The mixture was triturated with water/chloroform, the organic layer was separated, washed with brine, dried over magnesium sulfate, and evaporated to obtain crude isopropyl <strong>[55687-34-8]7-bromo-3-oxo-3,4-dihydroquinoxaline</strong>-1(2H)-carboxylate(9.3 g, 97%). A sample was recrystallized from ethanol: mp. 159-161 C. 1H-NMR (DMSO-d6) delta1.25 (d, J=6.2 Hz, 6H), 4.25 (s, 2H), 4.90 (sep, J=6.2 Hz, 1H), 6.89 (d, J=8.6 Hz, 1H), 7.27 (dd, J=9.1, 2.1 Hz, 1H), 7.74 (s, 1H), 12.51 (s, 1H), MS (ESI) m/z 330/332 (M+NH4)+. The title compound was prepared according to the procedure for Example 5 from isopropyl <strong>[55687-34-8]7-bromo-3-oxo-3,4-dihydroquinoxaline</strong>-1 (2H)-carboxylate (6.3 g, 20 mmol), and 3-chlorophenyl boronic acid (3.2 g, 20 mmol). Off-white crystals (3.7 g, 49%): mp. 174-176 C. 1H-NMR (DMSO-d6) delta1.27 (d, J=6.4 Hz, 6H), 4.30 (s, 2H), 4.94 (sep, J=6.2 Hz, 1H), 7.04 (d, J=8.3 Hz, 1H), 7.50 (m, 4H), 7.61 (t, J=1.9 Hz, 1H), 7.86 (s, 1H), 10.79 (s, 1H), MS(APCI) m/z 345/347 (M+H)+.
97%	In pyridine; toluene;	EXAMPLE 29 Isopropyl 7-(3-chlorophenyl)-3-oxo-3,4-dihydroquinoxalin-1(2H)-carboxylate To a solution of <strong>[55687-34-8]7-bromo-3-oxo-3,4-dihydroquinoxaline</strong> (6.8 g, 30 mmol) in pyridine (50 ml) was added a solution of isopropyl chloroformate in toluene (35 ml, 1M, 35 mmol) over 30 minutes. The mixture was triturated with water/chloroform, the organic layer was separated, washed with brine, dried over magnesium sulfate, and evaporated to obtain crude isopropyl <strong>[55687-34-8]7-bromo-3-oxo-3,4-dihydroquinoxaline</strong>-1(2H)-carboxylate (9.3 g, 97%). A sample was recrystallized from ethanol: m p. 159-161 C. 1H-NMR (DMSO-d6) delta 1.25 (d, J=6.2 Hz, 6H), 4.25 (s, 2H), 4.90 (sep, J=6.2 Hz, 1H), 6.89 (d,J=8.6 Hz, 1H), 7.27 (dd,J=9.1, 2.1 Hz, 1H), 7.74(s, 1H), 12.51 (s, 1H), MS (ESI) m/z 330/332 (M+NH4)+. The title compound was prepared according to the procedure for Example 5 from isopropyl <strong>[55687-34-8]7-bromo-3-oxo-3,4-dihydroquinoxaline</strong>-1(2H)-carboxylate (6.3 g, 20 mmol), and 3-chlorophenyl boronic acid (3.2 g, 20 mmol). Off-white crystals (3.7 g, 49%): m.p. 174-176 C. 1H-NMR (DMSO-d6) delta 1.27 (d, J=6.4 Hz, 6H), 4.30 (s, 2H), 4.94 (sep, J=6.2 Hz, 1H), 7.04 (d, J=8.3 Hz, 1H), 7.50 (m, 4H), 7.61 (t, J=1.9 Hz, 1H), 7.86 (s, 1H), 10.79 (s, 1H), MS (APCI) m/z 345/347 (M+H)+.

References: [1]Patent: US6380235,2002,B1 .
[2]Patent: US6423699,2002,B1 .

13
[ 105-36-2 ]
[ 55687-34-8 ]
6-bromo-1-ethoxycarbonylmethylquinoxalin-2(1H)-one [ No CAS ]

Yield	Reaction Conditions	Operation in experiment
1.95 g (80%)	With hydrogenchloride; In N,N-dimethyl-formamide; mineral oil;	EXAMPLE 2 6-Bromo-1-ethoxycarbonylmethylquinoxaline-2,3(1H,4H)-dione Under a nitrogen atmosphere <strong>[55687-34-8]6-bromoquinoxalin-2(1H)-one</strong> (2.03 g, 9 mmol) (J.Med.Chem., 24, (1981), 93) was dissolved in 22 ml of dry DMF and sodium hydride (0.44 g, 10.8 mmol (60% mineral oil dispersion)) was added. After stirring for 2 h, ethyl bromoacetate (1.25 ml, 11.3 mmol) was added and the mixture was stirred for 3.5 h. The reaction mixture was poured onto crushed ice and acidified (pH=4.5) by addition of dilute hydrochloric acid. The precipitate was filtered off, washed with water and air dried. The crude product (containing a minor fraction of O-alkylated product) was triturated with ether (100 ml), the precipitate filtered off, washed with ether and dried to afford 1.95 g (80%) of pure 6-bromo-1-ethoxycarbonylmethylquinoxalin-2(1H)-one. 1 H-NMR (DMSO-d6):delta1.22 (t, 3H), 4.17 (q, 2H), 5.08 (s, 2H), 7.56 (d, 1H), 7.83 (dd, 1H), 8.09 (dd, 1H), 8.37 (s, 1H).

References: [1]Patent: US5166155,1992,A .

14
[ 55687-34-8 ]
[ 1261071-89-9 ]