Decarboxylation via Addition of Water to a Carboxyl Group: Acid Catalysis of Pyrrole-2-Carboxylic Acid

2009 ◽  
Vol 131 (33) ◽  
pp. 11674-11675 ◽  
Author(s):  
Scott O. C. Mundle ◽  
Ronald Kluger
Keyword(s):  
Carboxylic Acid ◽  
Acid Catalysis ◽  
Carboxyl Group

The inner salt 4-carboxy-2-(pyridinium-4-yl)-1H-imidazole-5-carboxylate monohydrate

2006 ◽  
Vol 62 (7) ◽  
pp. o2751-o2752 ◽  
Author(s):  
Ting Sun ◽  
Jian-Ping Ma ◽  
Ru-Qi Huang ◽  
Yu-Bin Dong
Keyword(s):  
Carboxylic Acid ◽  
Dihedral Angle ◽  
Title Compound ◽  
Acid Group ◽  
Planar Structure ◽  
Carboxyl Group ◽  
Carboxylic Acid Group ◽  
Pyridyl Group ◽  
Compound C

In the title compound, C10H7N3O4·H2O, one carboxyl group is deprotonated and the pyridyl group is protonated. The inner salt molecule has a planar structure, apart from the carboxylic acid group, which is tilted from the imidazole plane by a small dihedral angle of 7.3 (3)°.

Acid catalysis in the formation of dioxopiperazines from peptides containing tetrahydroisoquinoline-3-carboxylic acid at position 2

2009 ◽  
Vol 45 (6) ◽  
pp. 567-573 ◽  
Author(s):  
SANTE CAPASSO ◽  
FILOMENA SICA ◽  
LELIO MAZZARELLA ◽  
GIANFRANCO BALBONI ◽  
REMO GUERRINI ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
Acid Catalysis

Improved synthesis of anti-sesquinorbornene

1984 ◽  
Vol 62 (9) ◽  
pp. 1840-1844 ◽  
Author(s):  
Karl R. Kopecky ◽  
Alan J. Miller
Keyword(s):  
Acetic Acid ◽  
Sulfuric Acid ◽  
Carboxylic Acid ◽  
Lead Tetraacetate ◽  
Carboxyl Group ◽  
Silver Acetate ◽  
Benzenesulfonyl Chloride ◽  
Methoxide Ion ◽  
Hydrolysis Of ◽  
Monomethyl Ester

Treatment of methyl hydrogen decahydro-1,4:5,8-exo,endo-dimethanonaphthalene-4a,8a-dicarboxylate with lead tetraacetate in benzene – acetic acid replaces the carboxyl group by an acetoxy group. Hydrolysis of this product with 25% sulfuric acid at 130 °C forms 8a-hydroxydecahydro-1,4:5,8-exo,endo-dimethanonaphthalene-4a-carboxylic acid 10. The reaction between 10 and benzenesulfonyl chloride in pyridine containing triethylamine at 95 °C produces anti-sesquinorbornene 1 in 34% yield. In the absence of triethylamine 1 is converted to the hydrochloride. The iodohydroperoxide of 1 is converted by silver acetate at 0 °C to the diketone in a luminescent reaction. The 1,2-dioxetane could not be isolated. Decahydro-1,4:5,8-exo,exo-dimethanonaphthalene-4a,8a-dicarboxylic anhydride is converted slowly by methoxide ion in methanol at 150 °C to the monomethyl ester which then undergoes demethylation. The isomeric exo,endo anhydride undergoes reaction readily with methoxide ion at 80 °C.

Azoverdin -an Isopyoverdin

1996 ◽  
Vol 51 (11-12) ◽  
pp. 772-780 ◽  
Author(s):  
R Michalke ◽  
K Taraz ◽  
H Budzikiewiez
Keyword(s):  
Carboxylic Acid ◽  
Succinic Acid ◽  
Peptide Chain ◽  
Side Chain ◽  
Carboxyl Group ◽  
Amino Group ◽  
Present Evidence ◽  
N Terminus

For azoverdin, the siderophore of Azomonas macrocytogenes ATCC 12334, a pyoverdintype structure has been suggested. We now present evidence that it is actually an isopyoverdin. Also the sequence of the peptide chain has to be revised. Azoverdin comprises, therefore, the chromophore (3S)-5-amino-1,2-dihydro-8,9-dihydroxy-3H -pyrimido[1,2a]quinoline- 3-carboxylic acid whose amino group is bound to a succinamide residue while the carboxyl group is attached to the N -terminus of L-Hse-[2-(R-1-amino-3-hydroxypropyl)-3,4,5,6- tetrahydropyrimidine-65-carboxylic acid]-N5-acetyl-N5,-hydroxy-ᴅ-Orn-ᴅ-Ser-N5-acetyl-N5- hydroxy-ʟ-Orn. In addition to azoverdin congeners with succinic acid (azoverdin A ) and with ʟ-Glu (azoverdin G ), resp., instead of the succinamide side chain could be isolated.

Synthesis of amino acid diazoketones

1986 ◽  
Vol 64 (11) ◽  
pp. 2097-2102 ◽  
Author(s):  
George R. Pettit ◽  
Paul S. Nelson
Keyword(s):  
Amino Acid ◽  
Carboxylic Acid ◽  
Acid Chloride ◽  
Low Temperatures ◽  
Oxalyl Chloride ◽  
Acyl Chloride ◽  
Carboxyl Group ◽  
Carboxylic Acid Chloride ◽  
Active Esters ◽  
Active Ester

A study of carboxylic acid → diazoketone conversion was pursued employing the γ-carboxyl group of otherwise protected L-glutamic acids. The Arndt–Eistert route employing carboxylic acid chloride intermediates was found best (52% yield, 5b), performed at very low temperatures employing oxalyl chloride in dimethylformamide–tetrahydrofuran followed by diazomethane at −23 °C. Alternatively, substitution of a mixed carbonic anhydride for the acyl chloride led to very similar yields (57% of 5b) of diazoketones (5). Among a series of active ester intermediates (7) examined, only the ODnp (7d) and SPfp (7f) esters were found to react (23–26% yield), at least partially, with diazomethane. The latter two reactions appear to represent the first such examples employing active esters.

scholarly journals 4-Bromobenzoic acid–6-(4-bromophenyl)-3-methyl-1,2,4-triazolo[3,4-b][1,3,4]thiadiazole (1/1)

2012 ◽  
Vol 68 (4) ◽  
pp. o1185-o1186
Author(s):  
Kamini Kapoor ◽  
Vivek K. Gupta ◽  
Satya Paul ◽  
Seema Sahi ◽  
Rajni Kant
Keyword(s):  
Crystal Structure ◽  
Carboxylic Acid ◽  
Hydrogen Bonds ◽  
Maximum Deviation ◽  
Carboxyl Group ◽  
Stacking Interactions ◽  
Acid Molecule ◽  
Ring Plane ◽  
Title 1 ◽  
Benzene Ring Plane

In the title 1:1 co-crystal, C10H7BrN4S·C7H5BrO2, the triazolothiadiazole system is approximately planar [with a maximum deviation of 0.030 (4) Å] and forms a dihedral angle of 8.6 (1)° with the bromophenyl ring. In the carboxylic acid molecule, the carboxyl group is rotated by 6.4 (3)° out of the benzene ring plane. The crystal structure features O—H...N and C—H...O hydrogen bonds, π–π stacking interactions [centroid–centroid distances = 3.713 (2), 3.670 (2) and 3.859 (3) Å] and short S...N [2.883 (4) Å] contacts.

Elimination of carboxyl group in 3,8-dinitro-6-oxo-6H-dibenzo[b,d]pyran-10-carboxylic acid by the action of DMSO or DMFA

1984 ◽  
Vol 20 (12) ◽  
pp. 1396-1396 ◽  
Author(s):  
A. M. Andrievskii ◽  
E. N. Sidorenko ◽  
A. N. Poplavskil ◽  
K. M. Dyumaev
Keyword(s):  
Carboxylic Acid ◽  
Carboxyl Group
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