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Methyl 3,4-bis(cyclopropylmethoxy)benzoate
Xian-Chao Cheng,Jing-Jing Hou,Cheng-Zhi Xie,Run-Ling Wang
Acta Crystallographica Section E , 2011, DOI: 10.1107/s1600536811013158
Abstract: The title compound, C16H20O4, was obtained unintentionally as the byproduct of an attempted synthesis of methyl 3-(cyclopropylmethoxy)-4-hydroxybenzoate. In the crystal, the molecules are linked by intermolecular C—H...O interactions.
(Benzoylamino)methyl 4-Hydroxybenzoate  [PDF]
Emil Popovski,Kristina Mladenovska
Molbank , 2010, DOI: 10.3390/M658
Abstract: (Benzoylamino)methyl 4-hydroxybenzoate (“Benzamidomethylparaben”) ( 3) was obtained from a reaction of 4-hydroxybenzoic acid ( 2) with a dioxane suspension of (benzamidomethyl)triethylammonium chloride ( 1). The phenolic group in 2 cannot be benzamidomethylated with 1 in aqueous media.
1-[(Cyclopropylmethoxy)methyl]-6-(3,4-dimethoxybenzyl)-5-ethyl-1,2,3,4-tetrahydropyrimidine-2,4-dione ethanol hemisolvate  [cached]
Nasser R. El-Brollosy,Ali A. El-Emam,Omar A. Al-Deeb,Seik Weng Ng
Acta Crystallographica Section E , 2012, DOI: 10.1107/s1600536811055693
Abstract: The asymmetric unit of the compound, C20H26N2O5·0.5C2H5OH, consists of two tetrahydropyrimidine-2,4-dione molecules and an ethanol molecule. The pyrimidine rings are nearly planar (r.m.s. deviation = 0.006 in one molecule and 0.009 in the other); the C atom at the 5-position deviates by 0.083 (3) [0.064 (3) in the second molecule] from the mean plane and the C atom at the 6-position by 0.034 (3) [0.082 (3) in the second molecule]. In each molecule, the benzene ring is nearly perpendicular to the pyrimidine ring, the dihedral angle is 88.51 (8)° in one molecule and 84.70 (8)° in the other. The amino group of each tetrahydropyrimidine-2,4-dione molecule is a hydrogen-bond donor to the exocyclic O atom at the 2-position of an adjacent molecule, the hydrogen bond generating an inversion dimer in each case. The ethanol molecule forms a hydrogen bond to the methoxy O atom of one of two independent molecules.
1-[(Cyclopropylmethoxy)methyl]-5-ethyl-6-(4-methylbenzyl)-1,2,3,4-tetrahydropyrimidine-2,4-dione  [cached]
Nasser R. El-Brollosy,Ali A. El-Emam,Omar A. Al-Deeb,Seik Weng Ng
Acta Crystallographica Section E , 2012, DOI: 10.1107/s1600536811055681
Abstract: The pyrimidine ring in the title compound, C19H24N2O3, is nearly planar (r.m.s. deviation = 0.008 ); the C atom at the 5-position deviates by 0.054 (3) from the mean plane and the C atom at the 6-position by 0.006 (3) in the opposite direction. The benzene ring is approximately perpendicular to the pyrimidine ring [dihedral angle = 83.90 (10)°]. The amino group is hydrogen-bond donor to the exocyclic O atom at the 2-position of an adjacent molecule, the hydrogen bond generating an inversion dimer. The cyclopropyl ring is disordered over two sets of sites with the major component having 71.5 (4)% occupancy.
A second monoclinic polymorph of methyl 4-hydroxybenzoate
Hoong-Kun Fun,Samuel Robinson Jebas
Acta Crystallographica Section E , 2008, DOI: 10.1107/s1600536808017327
Abstract: A second monoclinic polymorph of methyl 4-hydroxybenzoate, C8H8O3, is reported. The unit-cell dimensions are different from those of the previously reported monoclinic form [Vujovic & Nassimbeni (2006). Cryst. Growth Des. 6, 1595–1597]. The asymmetric unit contains three crystallographically independent molecules, as observed in the previous form. The crystal structure is stabilized by intermolecular O—H...O and C—H...O hydrogen bonds and C—H...π interactions, which link the molecules into a three-dimensional network.
2,3-Diaminopyridinium 4-hydroxybenzoate
Hoong-Kun Fun,Kasthuri Balasubramani
Acta Crystallographica Section E , 2009, DOI: 10.1107/s1600536809020832
Abstract: In the title compound, C5H8N3+·C7H5O3 , the pyridine N atom is protonated. In the 4-hydroxybenzoate anion, the carboxylate group is twisted slightly out of the benzene ring plane by an angle of 3.77 (5)°. The protonated N atom and one of the two amino groups are hydrogen-bonded to the 4-hydroxybenzoate anion through a pair of N—H...O hydrogen bonds, forming an R22(8) ring motif. The crystal structure is further stabilized by O—H...O and C—H...O hydrogen bonds and π–π interactions involving the pyridinium rings [centroid–centroid distance of 3.6277 (5) ], leading to the formation of a three-dimensional network.
Methyl 4-bromo-3-hydroxybenzoate
Hua-Rong Huang,Zhi-Yun Du,Yu-Jing Lu,Yan-Xiong Fang
Acta Crystallographica Section E , 2011, DOI: 10.1107/s1600536810051445
Abstract: In the title compound, C8H7BrO3, the methoxycarbonyl group is twisted at a dihedral angle of 8.06 (4)° with respect to the benzene ring. In the crystal, molecules are connected by O—H...O hydrogen bonds into helical chains running along the b axis.
Methyl 4-benzyloxy-2-hydroxybenzoate  [cached]
B. S. Palakshamurthy,H. T. Srinivasa,Vijith Kumar,S. Sreenivasa
Acta Crystallographica Section E , 2012, DOI: 10.1107/s1600536812046491
Abstract: In the title compound, C15H14O4, the dihedral angle between the benzene rings is 67.18 (8)°. The Ca—Cm—O—Ca (a = aromatic and m = methylene) torsion angle is 172.6 (3)° and an intramolecular O—H...O hydrogen bond generates an S(6) ring. In the crystal, molecules are linked by C—H...O hydrogen bonds into zigzag chains propagating in [001] and C—H...π interactions also occur.
(Benzoylamino)methyl 4-[(Benzoylamino)methoxy]benzoate  [PDF]
Emil Popovski,Kristina Mladenovska,Ana Poceva Panovska
Molbank , 2011, DOI: 10.3390/M711
Abstract: In this note, two procedures for the synthesis of (benzoylamino)methyl 4-[(benzoylamino)-methoxy]benzoate ( 3) are presented. The first procedure is carried out in dioxane/water using benzoylaminomethyl-4-hydroxybenzoate, while the second one employs a suspension of 4-hydroxy-benzoic acid in dioxane. In both procedures, benzamidomethyl triethylammonium chloride is used for the benzamidomethylation reaction.
Genomic and Functional Analyses of the Gentisate and Protocatechuate Ring-Cleavage Pathways and Related 3-Hydroxybenzoate and 4-Hydroxybenzoate Peripheral Pathways in Burkholderia xenovorans LB400  [PDF]
María José Romero-Silva, Valentina Méndez, Loreine Agulló, Michael Seeger
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0056038
Abstract: In this study, the gentisate and protocatechuate pathways in Burkholderia xenovorans LB400 were analyzed by genomic and functional approaches, and their role in 3-hydroxybenzoate (3-HBA) and 4-hydroxybenzoate (4-HBA) degradation was proposed. The LB400 genome possesses two identical mhbRTDHI gene clusters encoding the gentisate pathway and one mhbM gene encoding a 3-HBA 6-hydroxylase that converts 3-HBA into gentisate. The pca genes encoding the protocatechuate pathway and the pobA gene encoding the 4-HBA 3-monooxygenase that oxidizes 4-HBA into protocatechuate are arranged in gene clusters and single genes mainly at the minor chromosome, but also at the major chromosome and the megaplasmid. Strain LB400 was able to grow on gentisate, protocatechuate, 3-HBA and 4-HBA. Transcriptional analyses showed that the mhbD gene encoding the gentisate 1,2-dioxygenase was expressed during growth on 3-HBA, 4-HBA and gentisate, whereas the pcaG gene encoding the protocatechuate 3,4-dioxygenase was expressed only during growth on 4-HBA and protocatechuate. The mhbM gene encoding the 3-HBA 6-hydroxylase was transcribed in strain LB400 during growth on HBAs, gentisate, protocatechuate and glucose. The pobA gene encoding the 4-HBA 3-monooxygenase was expressed during growth on HBAs and glucose. 3-HBA- and 4-HBA-grown LB400 cells showed gentisate 1,2-dioxygenase activity, whereas protocatechuate 3,4-dioxygenase activity was observed only in 4-HBA-grown cells. The mhbR gene encoding a MarR-type transcriptional regulator that probably regulates the expression of the MhbT transporter, and the pcaQ and pcaR genes encoding LysR-type transcriptional regulators that regulate pcaHG and pcaIJBDC genes, respectively, were transcribed during growth on both HBAs, gentisate, protocatechuate and glucose, suggesting a basal constitutive expression. The results indicate active gentisate, protocatechuate, 3-HBA and 4-HBA catabolic pathways in B. xenovorans LB400 and suggest that 3-HBA is channeled exclusively through the gentisate route, whereas 4-HBA is funneled into the protocatechuate central pathway and potentially into the gentisate pathway.
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