Month: November 2022

van Iperen, Jolanda published the artcileCrystalline Deposits in New Display Cases at the Rijksmuseum: Characterisation and Origin, Application of Bis(2,2,6,6-tetramethylpiperidin-4-yl) decanedioate, the main research area is raman spectroscopy carboxylic acid.

An unusual phenomenon occurred in new display cases at the Rijksmuseum four months after their installation in Apr. 2013. White deposits were visible on glass windows, silicone door gaskets, black structural adhesive seals, and on works of art. The works of art most affected by these deposits were bronze sculptures, wooden and waxed objects, tempera, and oil paintings. It was found that TMP-ol, which is part of the UV-light stabilizer Tinuvin-770, emitted from the structural adhesive Terostat-9220. Terostat-9220 was used in large quantities in the display cases to adhere glass windows to metal parts. The carboxylic acids derived from both construction materials used to build the cases and from conservation materials present on the exhibited works of art. The carboxylic acids involved were 2,4-dichlorobenzoic acid, formic acid, methacrylic acid, palmitic acid, and an unknown carboxylic acid, resp. emitted from peroxide-cured silicone gaskets, panels of medium-d. fiberboard (MDF), UV-adhesive, beeswax containing products, and from an unknown acidic conservation product or binding medium. The identification of the crystalline deposits was supported by their syntheses in the laboratory Since 2013, similar deposits have been observed in a number of museum collections worldwide. A treatment for preventing further growth of the deposits was developed and applied in the Rijksmuseum showcases.

Studies in Conservation published new progress about Beeswax. 52829-07-9 belongs to class piperidines, name is Bis(2,2,6,6-tetramethylpiperidin-4-yl) decanedioate, and the molecular formula is C28H52N2O4, Application of Bis(2,2,6,6-tetramethylpiperidin-4-yl) decanedioate.

Referemce:
Piperidine – Wikipedia,
Piperidine | C5H11N – PubChem

Tantry, Subramanyam J. published the artcileWhole cell screen based identification of spiropiperidines with potent antitubercular properties, Recommanded Product: tert-Butyl spiro[indene-1,4′-piperidine]-1′-carboxylate, the main research area is spiropiperidine antitubercular; Antimycobacterial; Hypoxic conditions; MmpL3; Non-replicating phase; Whole cell screen; ss18b.

Whole cell based screens to identify hits against Mycobacterium tuberculosis (Mtb), carried out under replicating and non-replicating (NRP) conditions, resulted in the identification of multiple, novel but structurally related spiropiperidines with potent antitubercular properties. These compounds could be further classified into three classes, namely, 3-(3-aryl-1,2,4-oxadiazol-5-yl)-1′-alkylspiro[indene-1,4′-piperidine] (abbr. spiroindenes), 4-(3-aryl-1,2,4-oxadiazol-5-yl)-1′-alkylspiro[chromene-2,4′-piperidine] (abbr. spirochromenes) and 1′-benzylspiro[indole-1,4′-piperidin]-2(1H)-one (abbr. spiroindolones). Spiroindenes showed ≥4 log10 kill (at 2-12 μM) on replicating Mtb, but were moderately active under non replicating conditions. Whole genome sequencing efforts of spiroindene-resistant mutants resulted in the identification of the I292L mutation in MmpL3 (Mycobacterial membrane protein Large), required for the assembly of mycolic acid into the cell wall core of Mtb. MIC modulation studies demonstrated that the mutants were cross-resistant to spirochromenes but not to spiroindolones. This paper describes lead identification efforts to improve potency while reducing the lipophilicity and hERG liabilities of spiroindenes. Addnl., as deduced from the SAR studies, the authors provide insights regarding the new chem. opportunities that the spiroindolones can offer to the TB drug discovery initiatives.

Bioorganic & Medicinal Chemistry Letters published new progress about Mutation. 137419-24-0 belongs to class piperidines, name is tert-Butyl spiro[indene-1,4′-piperidine]-1′-carboxylate, and the molecular formula is C18H23NO2, Recommanded Product: tert-Butyl spiro[indene-1,4′-piperidine]-1′-carboxylate.

Referemce:
Piperidine – Wikipedia,
Piperidine | C5H11N – PubChem

Peindy N’Dongo, Harmel W. published the artcilePreparation and biological evaluation of cyclopentadienyl-based 99mTc-complexes [(Cp-R)99mTc(CO)3] mimicking benzamides for malignant melanoma targeting, Quality Control of 1205-72-7, the main research area is cyclopentadienyl technetium 99m complex preparation melanoma imaging.

The biol. evaluation of half-sandwich 99mTc-complexes that surrogate iodobenzamide with a high affinity for melanin tumor tissue is described. We have synthesized via retro Diels-Alder reaction two models of 99mTc complexes which possess the piano stool [Cp99mTc(CO)3] motif instead of a Ph ring as in the original iodobenzamide 123I-N-(N-benzylpiperidin-4-yl)-2-iodobenzamide (2-IBP) and N-(2-diethylaminoethyl)-4-iodobenzamide (BZA). Diels-Alder products 2a-2b (HCp-CONHR)2 (2a, R=2-diethylaminoethyl; 2b, R=benzylpiperidin-4-yl) were prepared and reacted with fac-[99mTc(H2O)3(CO)3]+ 1 in water to produce the corresponding 99mTc complexes [(2a)99mTc(CO)3] 4a and [(2b)99mTc(CO)3] 4b. The structures of the 99mTc complexes on the no-carrier-added level have been confirmed by chromatog. comparison with the corresponding rhenium complexes and, macroscopically characterized by IR, NMR, ESI-MS and X-ray crystallog. for [triclinic, P-1, a=7.3518(1) Å, b=8.0309(2) Å, c=17.5536(3) Å, α=99.1260(5)°, β=90.4215(14)°, γ=117.0187(11)°]. The radioconjugate showed good in vitro stability. In murine melanoma B16F1 cells, significant cellular uptake (43.9% of the total applied activity) was attained after 4 h at 37°C with about 50% of the cell-associated radioactivity being internalized in the cells (22% of the applied activity). Furthermore, in melanoma-bearing C57BL6 mice, tumor uptake values of 3.39±0.50 %ID g-1 and 3.21±0.26 %ID g-1 at 1 and 4 h postinjection, resp., were observed indicating a good retention of in the tumor.

Nuclear Medicine and Biology published new progress about Melanoma. 1205-72-7 belongs to class piperidines, name is 1-Benzylpiperidin-4-amine dihydrochloride, and the molecular formula is C12H20Cl2N2, Quality Control of 1205-72-7.

Referemce:
Piperidine – Wikipedia,
Piperidine | C5H11N – PubChem

Ye, Wenjun published the artcileDesign, synthesis and biological evaluation of novel triazoloquinazolinone and imidazoquinazolinone derivatives as allosteric inhibitors of SHP2 phosphatase, Product Details of C10H20N2O2, the main research area is melanoma SHP2 phosphatase triazoloquinazolinone imidazoquinazolinone; SHP2; allosteric inhibitors; antitumor activity; synthesis.

A series of novel triazoloquinolinone and imidazoquinazolinone derivatives were designed and synthesized, and their biol. activities against SHP2 protein and melanoma A357 cell line were evaluated in vitro. The results show that some target compounds have moderate to excellent inhibitory activity on SHP2 protein and melanoma A357 cell line. Structure-activity relationships (SARs) showed that both imidazoquinazolinone and triazoloquinazolinone derivatives have good SHP2 protein kinase and melanoma cell line A357 inhibitory activity. The results of mol. docking also showed that the cores of imidazoquinazolinone and triazoloquinazolinone have a certain affinity for SHP2 protein at the same time. Compared with SHP244, the target compounds have quite good liver microsomal stability and has more drug potential. The most promising compound has a strong inhibitory effect on the melanoma cell line A357 at 100 μM (76.15% inhibition).

Journal of Enzyme Inhibition and Medicinal Chemistry published new progress about Melanoma. 73874-95-0 belongs to class piperidines, name is tert-Butyl piperidin-4-ylcarbamate, and the molecular formula is C10H20N2O2, Product Details of C10H20N2O2.

Referemce:
Piperidine – Wikipedia,
Piperidine | C5H11N – PubChem

Malesevic, Miroslav published the artcileAn improved method for the solution cyclization of peptides under pseudo-high dilution conditions, Application In Synthesis of 158922-07-7, the main research area is cyclopeptide solid phase synthesis; macrocyclization solid phase solution pseudo high dilution.

Depending on the ring size, the cyclization of peptides often is accompanied by dimerization or cyclodimerization. Hence, these macrocyclizations have to be performed under high dilution conditions. Efficient cyclization of peptides in solution with a min. amount of solvent succeeds, when a dual syringe pump is used to simultaneously add the linear peptide precursor and a coupling reagent from two sep. syringes.

Journal of Biotechnology published new progress about Dilution. 158922-07-7 belongs to class piperidines, name is 1-(((9H-Fluoren-9-yl)methoxy)carbonyl)piperidine-3-carboxylic acid, and the molecular formula is C21H21NO4, Application In Synthesis of 158922-07-7.

Referemce:
Piperidine – Wikipedia,
Piperidine | C5H11N – PubChem

Kasuga, Seiki published the artcileHeteroalicyclic aminoalkanols. I. Syntheses of DL-2-piperidylmethanol and meso-cis-2,6-bis(hydroxymethyl)piperidine and reactions of intermediates, Computed Properties of 27483-92-7, the main research area is ALCOHOLS; CHEMISTRY, PHARMACEUTICAL; EXPERIMENTAL LAB STUDY; PIPERIDINES; PYRIDINES.

2-Acetoxymethyl-6-methyl- pyridine 1-oxide (I) (20 g.) in 100 cc. 48% aqueous HBr refluxed 4 h. yielded 27.1 g. 2-BrCH2 analog (II) of I.HBr, colorless rods, m. 123-4° (Me2CO). 2,6-Bis(acetoxymethyl)pyridine 1-oxide (10 g.) yielded similarly 10.5 g. 2,6-bis(bromomethyl)pyridine 1-oxide (III), granules, m. 153-5° (MeOH). 2-Bromomethylpyridine 1-oxide-HBr (IV.HBr) (5 g.) treated with alkali, and the free IV heated 2.5 h. on the water bath with 1.2 cc. CS(NH2)2 in 100 cc. EtOH yielded 3.5 g. 2-(2-pyridylmethyl)-2-thiopseudourea N-oxide-HBr (V.HBr), rods, m. 184-5° (decomposition) (MeOH). II yielded similarly the 2-(6-methyl-2-pyridylmethyl) analog (VI) of V.HBr, rods, m. 191-2° (EtOH). III gave similarly 65% VII.2HBr, granules, m. 203-5° (decomposition). Na (0.34 g.) in 23 cc. absolute EtOH treated with dry H2S until alk. and then with IV in EtOH from 5 g. IV.HBr, and the resulting gummy product dissolved in 5 cc. 4N alc. HCl with warming, filtered from some bis-(1-oxo-2-pyridylmethyl) disulfide-2HCl (VIII.2HCl), and worked up yielded 2-pyridylmethanethiol 1-oxide-HCl (IX.HCl), rods, m. 114-15° (Me2CO). II gave similarly the 6-Me derivative (X) of IX.HCl, 21%, rods, m. 133-4° (EtOH), and some 6,6′-dimethyl derivative (XI) of VIII, m. 160-4°. VI (0.2 g.) in 0.6 cc. 2N NaOH heated 2 h. on the water bath under N, cooled, and acidified with alc. HCl yielded 0.02 g. X.2HCl, m. 132-3° (Et2O-EtOH). IV from 3 g. IV.HBr heated 2 h. on the water bath with 5 cc. H2O containing 1.34 g. Na2S.9H2O yielded 0.5 g. bis(1-oxo-2-pyridylmethyl) sulfide (XII), yellow rods, m. 1745° (decomposition); picrate m. 148° (EtOH). II gave similarly 35% 6,6′-dimethyl derivative of XII, light yellow rods, m. 121-2° (AcOEt); XI.2HCl, granules, m. 163-4° (EtOH). Na2S.9H2O (1.34 g.) and 0.23 g. S in 10 cc. H2O heated 2 h. on the water bath with IV from 3 g. IV.HBr, and the gummy product treated with 3 cc. 4N alc. HCl yielded 0.3 g. VlII.2HCl, rods, m. 1623° (decomposition) (MeOH); picrate m. 139-40° (EtOH). IX in EtOH aerated overnight gave VIII which was converted to the picrate, m. 135-9°. II treated with Na2S yielded 28% XI.2HCl, m. 192-3° (decomposition). X oxidized with air and treated with HCl gave 38.5% XI.2HCl, m. 192-3° (decomposition). IV from 2.8 g. IV.HBr stirred 2 h. with 40 cc. H2O containing 2.7 g. EtSNa yielded 0.5 g. oily, yellowish 2-ethylthiomethylpyridine 1-oxide (XIII), b6, 134-7°; picrolonate, m. 137° (EtOH). II gave similarly 39% yellow, oily 6-Me derivative of XIII, b3 143-6°; picrolonate m. 120.5-21° (EtOH). II (1 g.) refluxed 4 h. with 5 cc. Ac2O yielded 0.5 g. pink oil, b2 90-115° which refluxed 4 h. with 10 cc. 47% aqueous HBr gave 0.28 g. III.HBr, m. 208-10° (decomposition) (EtOH); the filtrate treated with 2,4-(O2N)2C6H3-NHNH2 in aqueous H3PO4 yielded 6-methylpyridine-2-carboxaldehyde 2,4-dinitrophenylhydrazone (XIV), m. 231-3° (decomposition). X in Ac2O refluxed 3 h. under N yielded 21% 6-methyl-2-pyridylmethanethiol acetate (XV), yellow oil, b5 112-14°; picrolonate m. 164-5° (decomposition) (EtOH). 2-Ethylthiomethyl-6-methylpyridine 1-oxide (3 g.) in 9 cc. Ac2O refluxed 4 h. yielded 3.4 g. 2-(acetoxy)(ethylthio)methyl-6-methylpyridine (XVI), pink oil, b5 143-4°; picrate m. 105-7° (aqueous EtOH). XVI (1 g.) and 20 cc. 20% aqueous HCl refluxed 10 h. under N (EtSH evolved) yielded 0.46 g. oil, b12 77-8°, which gave XIV, m. 230°. IV.HBr (1 g.) in 6 cc. 2N NaOH kept 1 h. at room temperature gave 0.41 g. bis-(1-oxo-2-pyridylmethyl) oxide H2O (XVII.H2O), needles, m. 128-9° (AcOEt); picrate m. 192-3° (EtOH). Bis(2-pyridylmethyl) oxide (XVIII) (0.2 g.), 2 cc. AcOH, and 0.4 cc. 30% H2O2 heated 12 h. at 70-80° gave 0.1 g. XVII.H2O, m. 127°. XVII.H2O (0.3 g.) in 15 cc. 48% HBr refluxed 7 h. yielded IV, isolated as the picrate, m. 129-30°. XVII.H2O (0.4 g.) in 30 cc. CHCl3 heated 1 h. on the water bath with 0.3 cc. PCl3 and basified with aqueous K2CO3 gave 0.23 g. oily XVIII, b4 146-8°; picrate m. 197-8° (decomposition) (EtOH). 2-Pyridylmethanol (XIX) (2 g.) in 10 cc. xylene treated with stirring and cooling with 5.4 g. concentrated H2SO4 and heated 5 h. at 160-70° with the azeotropic removal of H2O gave 1.6 g. unreacted XIX, b8 100-5°, and 0.22 g. XVIII, b3 145-8°. 2-Bromomethylpyridine-HBr (XX.HBr) (1 g.) stirred 5 h. with 10 cc. 2N NaOH gave 0.21 g. XIX, b4 74-80°, and 0.23 g. XVIII, b4 80-124°. II treated with PCl3 gave 82.3% bis(1-oxo-6-methyl-2-pyridylmethyl) oxide-0.5H2O (XXI.-0.5H2O), needles, m. 175-7° (MeOH); picrate m. 174-5° (EtOH). 6,6′-Dimethyl derivative (XXII) of XVIII in xylene refluxed with concentrated H2SO4 gave 78.5% XXI.0.5H2O. 6-Me derivative (XXIII) of XIX gave similarly unreacted XXIII and 33.8% XXII, b4 150-5°, which yielded a dipicrate, m. 210-12° (decomposition). The 6-Me derivative of XX stirred 5 h. with 2N NaOH yielded 63.2% XXII, m. 75-6° (H2O). XVII.H2O (5 g.) and 30 cc. Ac2O refluxed 4 h. yielded 1.4 g. picolinecarboxaldehyde diacetate, b3 118-23° [picrate m. 146-7° (EtOH)], and 2.15 g. 2-pyridylmethyl picolinate (XXIV), b0.05 155-7°, m. 52-3° (ligroine). Picolinic acid (1.6 g.) in 3 cc. C6H6 treated with cooling and stirring with 6 cc. concentrated H2SO4 and 1.1 g. XIX, and the mixture refluxed with the overhead removal of H2O-C6H6 azeotrope and the dropwise addition of C6H6 during 6 h., poured onto ice, and basified with aqueous K2CO3 yielded 0.5 g. unreacted XIX and 0.26 g. XXIV, m. 52-3° (ligroine). XIX (50 g.) in 50 cc. EtOH hydrogenated 7 h. with stirring at 80° and 200 atm. initial pressure over 50 cc. Raney Ni W-2 yielded 47.8 g. 2-piperidylmethanol, b13 108°; picrate m. 133-5° (EtOH). Di-Me meso-cis-2,6-piperidinedicarboxylate (1 g.), 0.5 g. LiAlH4, and 40 cc. Et2O refluxed 3 h. yielded 1.5 g. meso-cis-2,6-bis(hydroxymethyl)piperidine (XXV), plates, m. 130-1° (AcOEt). 2,6-Bis(hydroxymethyl)pyridine (4 g.) in 20 cc. EtOH hydrogenated over 10 cc. Raney Ni yielded 3.4 g. XXV. Di-Me 2,6-pyridinedicarboxylate (3.5 g.) in 35 cc. MeOH hydrogenated over 15 cc. Raney Ni gave 2.2 g. XXV, plates, m. 128-30°.

Chemical & Pharmaceutical Bulletin published new progress about Alcohols. 27483-92-7 belongs to class piperidines, name is 2-(Chloromethyl)-1-methylpiperidine hydrochloride, and the molecular formula is C7H15Cl2N, Computed Properties of 27483-92-7.

Referemce:
Piperidine – Wikipedia,
Piperidine | C5H11N – PubChem

Taguchi, Tanezo published the artcileHeteroalicyclic aminoalkanols. II. Reactions of DL-2-piperidylmethanol involving the formation of DL-1-azabicyclo[4.1.0]heptane, Quality Control of 27483-92-7, the main research area is .

2-Piperidylmethanol (I) (5 g.) in 5 cc. Et2O treated simultaneously with stirring at 0° with 6 g. BzCl in 20 cc. Et2O and 20 cc. aqueous NaOH and stirred 1 h. at room temperature yielded 7.2 g. 1-Bz derivative (II) of I, granules, m. 94-5° (Et2O). II (0.5 g.) in 20 cc. 2% aqueous HCl gave 0.53 g. benzoate (III) of I.HCl, rods, m. 243-4° (MeOH-EtOH). II with 2% HBr gave similarly 91% I.HBr, needles, m. 233-4° (decomposition) (EtOH). III.HCl (0.2 g.) stirred 0.5 h. with 10 cc. 5% aqueous NaOH yielded 0.15 g. II, granules, m. 74° (Et2O). I (1.15 g.) in 10 cc. Et2O treated dropwise with 9 cc. aqueous NaOH and then with 3 g. BzCl and stirred 3 h. yielded 2.8 g. 1-benzoyl-2-piperidylmethanol benzoate (IV), granules, m. 65-7° (Et2O-ligroine). II (0.5 g.) in 5 cc. C6H6 and 5 cc. 10% aqueous NaOH treated dropwise with stirring with 0.4 g. BzCl gave 0.66 g. IV, m. 65°. I ( 1 g.), 0.88 cc. BzH, and 10 cc. C6H6 refluxed 1 h. with 1 cc. AcOH with the azeotropic removal of H2O gave 1.3 g. V, b8 134-6°. V (0.5 g.) in 2 cc. CHCl3 treated dropwise with cooling and stirring with 0.4 g. Br in 2 cc. CHCl3 and then stirred with 2 cc. 10% aqueous NaOH gave 0.67 g. III.HBr, needles, m. 233° (EtOH). 2-ClCH2 analog (VI) (4 g.) of I.HCl and 2 g. CS(NH2)2 in 12 cc. EtOH refluxed 10 h. gave 2.5 g. 2-(2-pyridylmethyl)-2-thiopseudourea-2HCl (VIa.2HCl), needles, m. 182-4° (EtOH), and 0.8 g. VII.HCl, rods, m. 186-8° (BuOH). VIa.2HCl (0.2 g.) in 2 cc. BuOH refluxed 1 h. yielded 0.18 g. VII.HCl, needles, m. 186-8° (BuOH). VIa.2HCl (50 mg.) in 2 cc. EtOH treated successively with 0.57 cc. 2% alc. KOH, 41 mg. 2,4-(O2N)2C6H3Cl in 2 cc. EtOH, and 1.14 cc. 2% alc. KOH yielded 25 mg. 1-(2,4-dinitrophenylamidino)-2-(2,4-dinitrophenylthiomethyl)piper-idine, brownish yellow granules, m. 185-7° (decomposition). 1-Methyl-2-piperidylmethanol (VIII) (3 g.) in 30 cc. dry Et2O and then 1.8 cc. CS2 added dropwise with cooling and stirring to 0.46 g. powd. Na in 25 cc. dry Et2O, treated with 1.24 cc. MeI in 5 cc. dry Et2O, and worked up gave 3.1 g. Me 1-methyl-2-piperidylmethyl xanthate (IX), yellow oil; picrate, yellow needles, m. 124-6° (EtOH); IX.HCl m. 134-5° (EtOH-Et2O). The alk. hydrolysis of IX yielded VIII. VIII (4 g.) heated 0.5 h. at 130° yielded 3.5 g. S-(1-methyl-2-piperidylmethyl) S’-Me dithiolcarbonate (X), light yellow oil, b1 119-20°; picrate m. 164-5° (EtOH). VIII (7 g.) in 20 cc. dry CHCl3 refluxed 3 h. with 6 cc. SOCl2 gave 7.1 g. 2-ClCH2 analog (XI) of VIII.HCl, needles, m. 159-61° (Me2CO). XI.HCl (3 g.) and 1.23 g. CS(NH2)2 in 10 cc. EtOH refluxed 4 h. yielded 2.8 g. 2-(1-methyl-2-piperidylmethyl)-2-thiopseudourea-2HCl (XII.2HCl), needles, m. 192-3° (BuOH). XII.2HCl (0.7 g.) heated 1 h. on the water bath with 5 cc. 2N NaOH and treated with a stream of air gave 0.68 g. bis(1-methyl-2-piperidylmethyl) disulfide (XIII); dipicrate m. 153-5° (MeOH). X (1 g.) and 40 cc. 5% alc. NaOH heated I hr. on the water bath, treated dropwise with 10% alc. HCl (EtSH evolved), and the crude product treated in aqueous K2CO3 with air overnight yielded 0.8 g. XIII picrate, m. 151-4° (MeOH). VIII.MeI (8 g.) and Ag2O from 12 g. AgNO3 and 20 cc. 10N NaOH stirred 5 h., filtered, and evaporated, and the residue heated 3 h. at 100° in vacuo under N gave 1 g. VIII and 1.1 g. Me2N(CH2)5CHO, b3 168-70°; picrate m. 146-8° (H2O). I (6 g.) added with cooling to 5 cc. concentrated H2SO4 and heated gradually to 240° yielded 7.4 g. 2-HO3SOCH2 analog (XIV) of I, rods, m. 262-3° (decomposition) (MeOH). XIV (6 g.) in 40 cc. H2O and 100 cc. 10% aqueous NaOH distilled and the distillate treated with solid KOH gave 0.2 g. XV, b80 65°, which polymerized completely within several hrs., even under N; XV picrate m. 151-2° (Et2O-AcOEt). XV (0.1 g.) in Et2O stirred 1 h. and treated with K2CO3, and the basic product treated with picric acid gave the picrate of I, m. 115° (EtOH-Et2O). XV (0.1 g.) in Et2O treated with dry HCl and kept overnight gave VI.HCl, m. 187-8°. XV (0.1 g.) in Et2O treated overnight with 0.1 g. MeBr in Et2O gave 0.16 g. 2-bromomethyl-1,1-dimethylpiperidinium bromide (XVI), granules, m. 230° (EtOH). XV (0.14 g.), 0.1 g. CS(NH2)2, 1.32 cc. N HCl, and 2 cc. H2O stirred a few min., treated with an addnl. 1.32 cc. N HCl, and stirred 1 h., and the crude product refluxed 1 h. in BuOH gave VII isolated as the picrate, m. 1523° (H2O). I (3 g.) in 30 cc. 48% aqueous HBr refluxed 10 h. yielded 4.1 g. 2-bromomethylpiperidine-HBr (XVII.HBr), needles, m. 188-90° (EtOH). XVII.HBr (0.5 g.) in 10 cc. Et2O treated overnight with 20 cc. 10% MeBr-Et2O gave 0.57 g. XVI, granules, m. 233-4° (decomposition) (EtOH).

Chem. Pharm. Bull. (Tokyo) published new progress about Alcohols. 27483-92-7 belongs to class piperidines, name is 2-(Chloromethyl)-1-methylpiperidine hydrochloride, and the molecular formula is C7H15Cl2N, Quality Control of 27483-92-7.

Referemce:
Piperidine – Wikipedia,
Piperidine | C5H11N – PubChem

Gomez, Elena published the artcile1,4-Dihydropicolinic acid derivatives: novel NADH analogues with an altered connectivity pattern, Synthetic Route of 1690-74-0, the main research area is alkylpyridinium reduction dithionite dihydropyridine NADH analog preparation.

Sodium dithionite reduction of α-substituted N-alkylpyridinium salts derived from picolinic acid derivatives afforded the corresponding 1,4-dihydropyridines with a new substitution pattern, in which the electron-withdrawing group is at the α-position. These compounds promote biomimetic reductions and are hence considered functional NADH analogs.

Tetrahedron Letters published new progress about Reduction. 1690-74-0 belongs to class piperidines, name is Methyl 1-methylpiperidine-2-carboxylate, and the molecular formula is C8H15NO2, Synthetic Route of 1690-74-0.

Referemce:
Piperidine – Wikipedia,
Piperidine | C5H11N – PubChem

Meenal, K. Mrs. published the artcileThallium(III) acetate oxidation of some substituted-4-piperidones: a kinetic and mechanistic study, COA of Formula: C6H11NO, the main research area is oxidation piperidone thallium 3 kinetics.

Kinetics of oxidation of 4-piperidone, 3-methyl-2,6-diphenyl-4-piperidone, 3-alkyl-, and 3,3- and 3,5-dimethylpiperidone with Tl3+ in aqueous acetic acid in the presence of sulfuric acid at constant ionic strength (μ = 2.25 M) at 30-55° have been investigated. The reactions obey second order kinetics. Dependence on acidity is unity added sodium sulfate does not have any effect. Activation parameters have been calculated and the structure-reactivity relationships discussed. A mechanism involving fast enolization step is postulated.

Journal of the Indian Chemical Society published new progress about Oxidation. 5773-58-0 belongs to class piperidines, name is 3-Methylpiperidin-4-one, and the molecular formula is C6H11NO, COA of Formula: C6H11NO.

Referemce:
Piperidine – Wikipedia,
Piperidine | C5H11N – PubChem

Zhang, Chaohong published the artcileTop-down strategy identifying molecular phase stabilizers to overcome microstructure instabilities in organic solar cells, Safety of Bis(2,2,6,6-tetramethylpiperidin-4-yl) decanedioate, the main research area is organic solar cell microstructure instability mol phase stabilizer.

The operational stability of organic solar cells (OSCs) is the essential barrier to commercialization. Compared to thermally-induced degradation, photo-stability of OSCs is far away from being resolved. Here, we demonstrate that the thermal- and photo-degradation of metastable bulk-heterojunction OSCs are governed by the same mechanism. Understanding the fundamental principles behind this mechanism is of significant importance to fully address the instability issues. Structural incompatibilities between the donor and acceptor mols. are identified as the main origin of the instability. Further, we introduce a top-down approach mainly based on their melting temperature and interaction parameters to rationally screen mol. phase stabilizers from a database with more than 10 000 small mols. Eventually, five chems. were selected to validate our concept and tested in unstable organic solar cells. 1,4-Piperazine, which possesses a high m.p., good miscibility with polymers and the capability of forming inter-mol. hydrogen bonding, can indeed stabilize the mixed amorphous phases, leading to significantly improved stability of otherwise metas table OSCs.

Energy & Environmental Science published new progress about Annealing. 52829-07-9 belongs to class piperidines, name is Bis(2,2,6,6-tetramethylpiperidin-4-yl) decanedioate, and the molecular formula is C28H52N2O4, Safety of Bis(2,2,6,6-tetramethylpiperidin-4-yl) decanedioate.

Referemce:
Piperidine – Wikipedia,
Piperidine | C5H11N – PubChem