accessibility menu, dialog, popup

UserName

Furans

Aromatiska organiska föreningar som består av en femledad ring med fyra kolatomer, en syreatom och två dubbelbindningar.
Molekylvikt (g/mol) 
  • (7)
  • (3)
  • (5)
  • (6)
  • (2)
  • (12)
  • (6)
  • (2)
  • (3)
  • (2)
  • (2)
  • (2)
  • (2)
  • (3)
  • (6)
  • (3)
  • (2)
  • (4)
  • (4)
  • (1)
  • (3)
  • (2)
  • (3)
  • (3)
  • (8)
  • (2)
  • (3)
  • (2)
  • (4)
  • (3)
  • (2)
  • (2)
  • (6)
  • (3)
  • (2)
  • (2)
  • (3)
  • (4)
  • (2)
  • (1)
  • (2)
  • (3)
  • (4)
  • (3)
  • (3)
  • (3)
  • (3)
  • (2)
  • (2)
  • (3)
  • (3)
  • (2)
  • (2)
  • (2)
  • (2)
  • (3)
  • (2)
  • (1)
  • (2)
Procent renhet 
  • (1)
  • (3)
  • (3)
  • (14)
  • (13)
  • (3)
  • (2)
  • (91)
  • (33)
  • (18)
  • (3)
Kvantitet 
  • (1)
  • (55)
  • (10)
  • (14)
  • (1)
  • (2)
  • (28)
  • (1)
  • (16)
  • (1)
  • (43)
  • (4)
  • (8)
Fysisk form 
  • (2)
  • (1)
  • (7)
  • (1)
  • (3)
  • (2)
  • (1)
  • (1)
  • (1)
  • (4)
  • (5)
  • (6)
Kokpunkt 
  • (1)
  • (3)
  • (1)
  • (3)
  • (3)
  • (3)
  • (2)
  • (2)
  • (4)
  • (1)
  • (3)
  • (4)
  • (2)

Filtrerade sökresultat

Produkter från vissa av våra leverantörer visas inte i filtrerade sökresultat. Vänligen Rensa alla filter för att se dessa produkter.

Begränsa resultat

Begränsa resultat

Kategori

Specialerbjudande

  • (4)

Varumärken

  • (1)
  • (38)
  • (85)
  • (60)

Molekylvikt (g/mol)

  • (7)
  • (3)
  • (5)
  • (6)
  • (2)
  • (12)
  • (6)
  • (2)
  • (3)
  • (2)
  • (2)
  • (2)
  • (2)
  • (3)
  • (6)
  • (3)
  • (2)
  • (4)
  • (4)
  • (1)
  • (3)
  • (2)
  • (3)
  • (3)
  • (8)
  • (2)
  • (3)
  • (2)
  • (4)
  • (3)
  • (2)
  • (2)
  • (6)
  • (3)
  • (2)
  • (2)
  • (3)
  • (4)
  • (2)
  • (1)
  • (2)
  • (3)
  • (4)
  • (3)
  • (3)
  • (3)
  • (3)
  • (2)
  • (2)
  • (3)
  • (3)
  • (2)
  • (2)
  • (2)
  • (2)
  • (3)
  • (2)
  • (1)
  • (2)

Procent renhet

  • (1)
  • (3)
  • (3)
  • (14)
  • (13)
  • (3)
  • (2)
  • (91)
  • (33)
  • (18)
  • (3)

Kvantitet

  • (1)
  • (55)
  • (10)
  • (14)
  • (1)
  • (2)
  • (28)
  • (1)
  • (16)
  • (1)
  • (43)
  • (4)
  • (8)

Fysisk form

  • (2)
  • (1)
  • (7)
  • (1)
  • (3)
  • (2)
  • (1)
  • (1)
  • (1)
  • (4)
  • (5)
  • (6)

Kokpunkt

  • (1)
  • (3)
  • (1)
  • (3)
  • (3)
  • (3)
  • (2)
  • (2)
  • (4)
  • (1)
  • (3)
  • (4)
  • (2)

Kvalitet

  • (3)
Sök på nyckelord:
1 – 15 av 79 Resultat
1

Nitrofurantoin, 98 %, Thermo Scientific Chemicals

CAS: 67-20-9 Molekylformel: C8H6N4O5 Molekylvikt (g/mol): 238.16 MDL-nummer: MFCD00003224 InChI-nyckel: NXFQHRVNIOXGAQ-YCRREMRBSA-N Synonym: nitrofurantoin,macrodantin,5-nitrofurantoin,furadantin,furadonine,nitrofurantoine,furadantine,furadantoin,furadoine,furadontin PubChem CID: 6604200 ChEBI: CHEBI:71415 LEDER: [O-][N+](=O)C1=CC=C(O1)\C=N\N1CC(=O)NC1=O

Molekylformel C8H6N4O5
PubChem CID 6604200
MDL-nummer MFCD00003224
CAS 67-20-9
InChI-nyckel NXFQHRVNIOXGAQ-YCRREMRBSA-N
LEDER [O-][N+](=O)C1=CC=C(O1)\C=N\N1CC(=O)NC1=O
ChEBI CHEBI:71415
Molekylvikt (g/mol) 238.16
Synonym nitrofurantoin,macrodantin,5-nitrofurantoin,furadantin,furadonine,nitrofurantoine,furadantine,furadantoin,furadoine,furadontin
2

Dietyl3,4-dihydroxifuran-2,5-dikarboxylat, 97 %, Thermo Scientific™

CAS: 6270-57-1 Molekylformel: C10H12O7 Molekylvikt (g/mol): 244.199 MDL-nummer: MFCD00092386 InChI-nyckel: JGCMPUKYPRCPRE-UHFFFAOYSA-N Synonym: 2,5-diethyl 3,4-dihydroxyfuran-2,5-dicarboxylate,diethyl 3,4-dihydroxy-2,5-furandicarboxylate,2,5-bis ethoxy hydroxy methylidene oxolane-3,4-dione,3,4-dihydroxy-furan-2,5-dicarboxylic acid diethyl ester,pubchem7048,maybridge4_000491,2,5-bis ethoxycarbonyl-3,4-dihydroxyfuran,2,5-bis ethoxy oxidanyl methylidene oxolane-3,4-dione,2z,5z-bis ethoxy hydroxy methylidene oxolane-3,4-dione,2e,5e-2,5-bis ethoxy hydroxy methylidene oxolane-3,4-dione PubChem CID: 234848 IUPAC-namn: dietyl-3,4-dihydroxifuran-2,5-dikarboxylat LEDER: CCOC(=O)C1=C(C(=C(O1)C(=O)OCC)O)O

Molekylformel C10H12O7
PubChem CID 234848
MDL-nummer MFCD00092386
IUPAC-namn dietyl-3,4-dihydroxifuran-2,5-dikarboxylat
CAS 6270-57-1
InChI-nyckel JGCMPUKYPRCPRE-UHFFFAOYSA-N
LEDER CCOC(=O)C1=C(C(=C(O1)C(=O)OCC)O)O
Molekylvikt (g/mol) 244.199
Synonym 2,5-diethyl 3,4-dihydroxyfuran-2,5-dicarboxylate,diethyl 3,4-dihydroxy-2,5-furandicarboxylate,2,5-bis ethoxy hydroxy methylidene oxolane-3,4-dione,3,4-dihydroxy-furan-2,5-dicarboxylic acid diethyl ester,pubchem7048,maybridge4_000491,2,5-bis ethoxycarbonyl-3,4-dihydroxyfuran,2,5-bis ethoxy oxidanyl methylidene oxolane-3,4-dione,2z,5z-bis ethoxy hydroxy methylidene oxolane-3,4-dione,2e,5e-2,5-bis ethoxy hydroxy methylidene oxolane-3,4-dione
3

2-furosyra, 98 %, Thermo Scientific Chemicals

CAS: 88-14-2 Molekylformel: C5H4O3 Molekylvikt (g/mol): 112.084 MDL-nummer: MFCD00003238 InChI-nyckel: SMNDYUVBFMFKNZ-UHFFFAOYSA-N Synonym: 2-furoic acid,2-furancarboxylic acid,pyromucic acid,2-carboxyfuran,furoic acid,furancarboxylic acid,alpha-furoic acid,alpha-furancarboxylic acid,2-furanoic acid,kyselina 2-furoova PubChem CID: 6919 ChEBI: CHEBI:30845 IUPAC-namn: furan-2-karboxylsyra LEDER: C1=COC(=C1)C(=O)O

Molekylformel C5H4O3
PubChem CID 6919
MDL-nummer MFCD00003238
IUPAC-namn furan-2-karboxylsyra
CAS 88-14-2
InChI-nyckel SMNDYUVBFMFKNZ-UHFFFAOYSA-N
LEDER C1=COC(=C1)C(=O)O
ChEBI CHEBI:30845
Molekylvikt (g/mol) 112.084
Synonym 2-furoic acid,2-furancarboxylic acid,pyromucic acid,2-carboxyfuran,furoic acid,furancarboxylic acid,alpha-furoic acid,alpha-furancarboxylic acid,2-furanoic acid,kyselina 2-furoova
4
Kampanjer är tillgängliga

2-furosyra, 98 %, Thermo Scientific Chemicals

CAS: 88-14-2 MDL-nummer: MFCD00003238 InChI-nyckel: SMNDYUVBFMFKNZ-UHFFFAOYSA-N Synonym: 2-furoic acid,2-furancarboxylic acid,pyromucic acid,2-carboxyfuran,furoic acid,furancarboxylic acid,alpha-furoic acid,alpha-furancarboxylic acid,2-furanoic acid,kyselina 2-furoova PubChem CID: 6919 ChEBI: CHEBI:30845 IUPAC-namn: furan-2-karboxylsyra LEDER: C1=COC(=C1)C(=O)O

PubChem CID 6919
MDL-nummer MFCD00003238
IUPAC-namn furan-2-karboxylsyra
CAS 88-14-2
InChI-nyckel SMNDYUVBFMFKNZ-UHFFFAOYSA-N
LEDER C1=COC(=C1)C(=O)O
ChEBI CHEBI:30845
Synonym 2-furoic acid,2-furancarboxylic acid,pyromucic acid,2-carboxyfuran,furoic acid,furancarboxylic acid,alpha-furoic acid,alpha-furancarboxylic acid,2-furanoic acid,kyselina 2-furoova
5

5-nitro-2-furaldehyd-diacetat, 98+%, Thermo Scientific Chemicals

CAS: 92-55-7 Molekylformel: C9H9NO7 Molekylvikt (g/mol): 243.171 MDL-nummer: MFCD00003244 InChI-nyckel: HSXKWKJCZNRMJO-UHFFFAOYSA-N Synonym: 5-nitro-2-furaldehyde diacetate,2-diacetoxymethyl-5-nitrofuran,5-nitro-2-furanmethanediol diacetate,5-nitrofurfural diacetate,5-nitrofurfurylidene diacetate,5-nitrofuran-2-yl methylene diacetate,nitrofuraldehyde diacetate,5-nitro-2-furfural diacetate,5-nitrofuraldehyde diacetate,5-nitro-2-furfuraldehyde diacetate PubChem CID: 7097 IUPAC-namn: [acetyloxi-(5-nitrofuran-2-yl)metyl]acetat LEDER: CC(=O)OC(C1=CC=C(O1)[N+](=O)[O-])OC(=O)C

Molekylformel C9H9NO7
PubChem CID 7097
MDL-nummer MFCD00003244
IUPAC-namn [acetyloxi-(5-nitrofuran-2-yl)metyl]acetat
CAS 92-55-7
InChI-nyckel HSXKWKJCZNRMJO-UHFFFAOYSA-N
LEDER CC(=O)OC(C1=CC=C(O1)[N+](=O)[O-])OC(=O)C
Molekylvikt (g/mol) 243.171
Synonym 5-nitro-2-furaldehyde diacetate,2-diacetoxymethyl-5-nitrofuran,5-nitro-2-furanmethanediol diacetate,5-nitrofurfural diacetate,5-nitrofurfurylidene diacetate,5-nitrofuran-2-yl methylene diacetate,nitrofuraldehyde diacetate,5-nitro-2-furfural diacetate,5-nitrofuraldehyde diacetate,5-nitro-2-furfuraldehyde diacetate
6

5-bromfurusyra, 99 %, Thermo Scientific Chemicals

CAS: 585-70-6 Molekylformel: C5H3BrO3 Molekylvikt (g/mol): 190.98 InChI-nyckel: YVTQHZDUDUCGRD-UHFFFAOYSA-N Synonym: 5-bromo-2-furoic acid,5-bromofuroic acid,5-bromo-furan-2-carboxylic acid,5-bromo-2-furancarboxylic acid,2-furancarboxylic acid, 5-bromo,5-bromo-2-furanecarboxylic acid,5-bromo furan-2-carboxylic acid,2-furoic acid, 5-bromo,t5oj bvq ee,5-bromofuroic?acid PubChem CID: 68511 IUPAC-namn: 5-bromofuran-2-karboxylsyra LEDER: C1=C(OC(=C1)Br)C(=O)O

Molekylformel C5H3BrO3
PubChem CID 68511
IUPAC-namn 5-bromofuran-2-karboxylsyra
CAS 585-70-6
InChI-nyckel YVTQHZDUDUCGRD-UHFFFAOYSA-N
LEDER C1=C(OC(=C1)Br)C(=O)O
Molekylvikt (g/mol) 190.98
Synonym 5-bromo-2-furoic acid,5-bromofuroic acid,5-bromo-furan-2-carboxylic acid,5-bromo-2-furancarboxylic acid,2-furancarboxylic acid, 5-bromo,5-bromo-2-furanecarboxylic acid,5-bromo furan-2-carboxylic acid,2-furoic acid, 5-bromo,t5oj bvq ee,5-bromofuroic?acid
7

3-furosyra, 99 %, Thermo Scientific Chemicals

CAS: 488-93-7 Molekylformel: C5H4O3 Molekylvikt (g/mol): 112.08 MDL-nummer: MFCD00005350 InChI-nyckel: IHCCAYCGZOLTEU-UHFFFAOYSA-N Synonym: 3-furoic acid,3-furancarboxylic acid,3-carboxyfuran,3-furanoic acid,unii-88a3s7rg98,3-furoate,3-furans,3-furanoate,pubchem6945,acmc-209kee PubChem CID: 10268 ChEBI: CHEBI:30846 IUPAC-namn: furan-3-karboxylsyra LEDER: OC(=O)C1=COC=C1

Molekylformel C5H4O3
PubChem CID 10268
MDL-nummer MFCD00005350
IUPAC-namn furan-3-karboxylsyra
CAS 488-93-7
InChI-nyckel IHCCAYCGZOLTEU-UHFFFAOYSA-N
LEDER OC(=O)C1=COC=C1
ChEBI CHEBI:30846
Molekylvikt (g/mol) 112.08
Synonym 3-furoic acid,3-furancarboxylic acid,3-carboxyfuran,3-furanoic acid,unii-88a3s7rg98,3-furoate,3-furans,3-furanoate,pubchem6945,acmc-209kee
8

3-furosyra, 99 %, Thermo Scientific Chemicals

CAS: 488-93-7 Molekylformel: C5H4O3 Molekylvikt (g/mol): 112.08 MDL-nummer: MFCD00005350 InChI-nyckel: IHCCAYCGZOLTEU-UHFFFAOYSA-N Synonym: 3-furoic acid,3-furancarboxylic acid,3-carboxyfuran,3-furanoic acid,unii-88a3s7rg98,3-furoate,3-furans,3-furanoate,pubchem6945,acmc-209kee PubChem CID: 10268 ChEBI: CHEBI:30846 IUPAC-namn: furan-3-karboxylsyra LEDER: OC(=O)C1=COC=C1

Molekylformel C5H4O3
PubChem CID 10268
MDL-nummer MFCD00005350
IUPAC-namn furan-3-karboxylsyra
CAS 488-93-7
InChI-nyckel IHCCAYCGZOLTEU-UHFFFAOYSA-N
LEDER OC(=O)C1=COC=C1
ChEBI CHEBI:30846
Molekylvikt (g/mol) 112.08
Synonym 3-furoic acid,3-furancarboxylic acid,3-carboxyfuran,3-furanoic acid,unii-88a3s7rg98,3-furoate,3-furans,3-furanoate,pubchem6945,acmc-209kee
9

4,5-dimetyl-2-furonsyra, 97 %, Thermo Scientific™

CAS: 89639-83-8 Molekylformel: C7H8O3 Molekylvikt (g/mol): 140.138 MDL-nummer: MFCD00085031 InChI-nyckel: BNVXYXRSJIWWDX-UHFFFAOYSA-N PubChem CID: 2774924 IUPAC-namn: 4,5-dimetylfuran-2-karboxylsyra LEDER: CC1=C(OC(=C1)C(=O)O)C

Molekylformel C7H8O3
PubChem CID 2774924
MDL-nummer MFCD00085031
IUPAC-namn 4,5-dimetylfuran-2-karboxylsyra
CAS 89639-83-8
InChI-nyckel BNVXYXRSJIWWDX-UHFFFAOYSA-N
LEDER CC1=C(OC(=C1)C(=O)O)C
Molekylvikt (g/mol) 140.138
10

3-brom-2-furonsyra, 97 %, Thermo Scientific™

CAS: 14903-90-3 Molekylformel: C5H3BrO3 Molekylvikt (g/mol): 190.98 MDL-nummer: MFCD00092761 InChI-nyckel: UZBGSJZFBUOJNE-UHFFFAOYSA-N PubChem CID: 605479 IUPAC-namn: 3-bromofuran-2-karboxylsyra LEDER: C1=COC(=C1Br)C(=O)O

Molekylformel C5H3BrO3
PubChem CID 605479
MDL-nummer MFCD00092761
IUPAC-namn 3-bromofuran-2-karboxylsyra
CAS 14903-90-3
InChI-nyckel UZBGSJZFBUOJNE-UHFFFAOYSA-N
LEDER C1=COC(=C1Br)C(=O)O
Molekylvikt (g/mol) 190.98
11

Metyl 2-brom-3-furoat, 97 %, Thermo Scientific™

CAS: 197846-06-3 Molekylformel: C6H5BrO3 Molekylvikt (g/mol): 205.01 MDL-nummer: MFCD09879944 InChI-nyckel: XXUUZVIMSVBWIQ-UHFFFAOYSA-N Synonym: methyl 2-bromo-3-furoate,3-furancarboxylic acid, 2-bromo-, methyl ester,2-bromofuran-3-carboxylic acid methyl ester,3-furancarboxylic acid,2-bromo-, methyl ester PubChem CID: 10845885 IUPAC-namn: metyl-2-bromofuran-3-karboxylat LEDER: COC(=O)C1=C(Br)OC=C1

Molekylformel C6H5BrO3
PubChem CID 10845885
MDL-nummer MFCD09879944
IUPAC-namn metyl-2-bromofuran-3-karboxylat
CAS 197846-06-3
InChI-nyckel XXUUZVIMSVBWIQ-UHFFFAOYSA-N
LEDER COC(=O)C1=C(Br)OC=C1
Molekylvikt (g/mol) 205.01
Synonym methyl 2-bromo-3-furoate,3-furancarboxylic acid, 2-bromo-, methyl ester,2-bromofuran-3-carboxylic acid methyl ester,3-furancarboxylic acid,2-bromo-, methyl ester
12

Metyl 5-(klormetyl)-2-furoat, 95 %, Thermo Scientific™

CAS: 2144-37-8 Molekylformel: C7H7ClO3 Molekylvikt (g/mol): 174.58 MDL-nummer: MFCD00020922 InChI-nyckel: PWXMEBZOKUPCST-UHFFFAOYSA-N Synonym: methyl 5-chloromethyl-2-furoate,methyl 5-chloromethyl furan-2-carboxylate,methyl 5-chloromethyl-2-furancarboxylate,5-chloromethyl-furan-2-carboxylic acid methyl ester,2-furancarboxylic acid, 5-chloromethyl-, methyl ester,5-chloromethylfuran-2-carboxylic acid methyl ester,pubchem24261,enamine_005466,acmc-1ck5d PubChem CID: 75065 IUPAC-namn: metyl-5-(klormetyl)furan-2-karboxylat LEDER: COC(=O)C1=CC=C(O1)CCl

Molekylformel C7H7ClO3
PubChem CID 75065
MDL-nummer MFCD00020922
IUPAC-namn metyl-5-(klormetyl)furan-2-karboxylat
CAS 2144-37-8
InChI-nyckel PWXMEBZOKUPCST-UHFFFAOYSA-N
LEDER COC(=O)C1=CC=C(O1)CCl
Molekylvikt (g/mol) 174.58
Synonym methyl 5-chloromethyl-2-furoate,methyl 5-chloromethyl furan-2-carboxylate,methyl 5-chloromethyl-2-furancarboxylate,5-chloromethyl-furan-2-carboxylic acid methyl ester,2-furancarboxylic acid, 5-chloromethyl-, methyl ester,5-chloromethylfuran-2-carboxylic acid methyl ester,pubchem24261,enamine_005466,acmc-1ck5d
13

Etyl(5-brombensofuran)-2-karboxylat, 95 %, Thermo Scientific™

CAS: 84102-69-2 Molekylformel: C11H9BrO3 Molekylvikt (g/mol): 269.094 InChI-nyckel: XLJWAHXKBCDQNP-UHFFFAOYSA-N PubChem CID: 735184 IUPAC-namn: etyl-5-brom-l-bensofuran-2-karboxylat LEDER: CCOC(=O)C1=CC2=C(O1)C=CC(=C2)Br

Molekylformel C11H9BrO3
PubChem CID 735184
IUPAC-namn etyl-5-brom-l-bensofuran-2-karboxylat
CAS 84102-69-2
InChI-nyckel XLJWAHXKBCDQNP-UHFFFAOYSA-N
LEDER CCOC(=O)C1=CC2=C(O1)C=CC(=C2)Br
Molekylvikt (g/mol) 269.094
14

2,4-dimetyl-3-furonsyra, 97 %, Thermo Scientific™

CAS: 15058-72-7 Molekylformel: C7H8O3 Molekylvikt (g/mol): 140.138 InChI-nyckel: JFXXYKVSLHRBAA-UHFFFAOYSA-N Synonym: 2,4-dimethyl-3-furoic acid,2,4-dimethyl-3-furancarboxylic acid,3-furancarboxylic acid, 2,4-dimethyl,2,4-dimethyl-furan-3-carboxylic acid,2,4-dimethylfurane-3-carboxylic acid PubChem CID: 638456 IUPAC-namn: 2,4-dimetylfuran-3-karboxylsyra LEDER: CC1=COC(=C1C(=O)O)C

Molekylformel C7H8O3
PubChem CID 638456
IUPAC-namn 2,4-dimetylfuran-3-karboxylsyra
CAS 15058-72-7
InChI-nyckel JFXXYKVSLHRBAA-UHFFFAOYSA-N
LEDER CC1=COC(=C1C(=O)O)C
Molekylvikt (g/mol) 140.138
Synonym 2,4-dimethyl-3-furoic acid,2,4-dimethyl-3-furancarboxylic acid,3-furancarboxylic acid, 2,4-dimethyl,2,4-dimethyl-furan-3-carboxylic acid,2,4-dimethylfurane-3-carboxylic acid
15

Etyl-5-(klorsulfonyl)-3-furoat, 95 %, Thermo Scientific™

CAS: 256373-91-8 Molekylformel: C7H7ClO5S Molekylvikt (g/mol): 238.638 MDL-nummer: MFCD11109333 InChI-nyckel: LEKOVVUPHAKDKN-UHFFFAOYSA-N Synonym: ethyl 5-chlorosulfonyl furan-3-carboxylate,ethyl 5-chlorosulfonyl-3-furoate,3-furancarboxylic acid,5-chlorosulfonyl-, ethyl ester,5-chlorosulfonyl-furan-3-carboxylic acid ethyl ester,2-chlorosulfonyl furan-4-carboxylic acid ethyl ester,3-furancarboxylic acid, 5-chlorosulfonyl-, ethyl ester PubChem CID: 10130959 IUPAC-namn: etyl-5-klorsulfonylfuran-3-karboxylat LEDER: CCOC(=O)C1=COC(=C1)S(=O)(=O)Cl

Molekylformel C7H7ClO5S
PubChem CID 10130959
MDL-nummer MFCD11109333
IUPAC-namn etyl-5-klorsulfonylfuran-3-karboxylat
CAS 256373-91-8
InChI-nyckel LEKOVVUPHAKDKN-UHFFFAOYSA-N
LEDER CCOC(=O)C1=COC(=C1)S(=O)(=O)Cl
Molekylvikt (g/mol) 238.638
Synonym ethyl 5-chlorosulfonyl furan-3-carboxylate,ethyl 5-chlorosulfonyl-3-furoate,3-furancarboxylic acid,5-chlorosulfonyl-, ethyl ester,5-chlorosulfonyl-furan-3-carboxylic acid ethyl ester,2-chlorosulfonyl furan-4-carboxylic acid ethyl ester,3-furancarboxylic acid, 5-chlorosulfonyl-, ethyl ester