- Substituent effects of N-alkyl groups on thermally induced polymerization behavior of 1,3-benzoxazines
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Thermally induced polymerizations of a series of 1,3-benzoxazines with a variety of substituents on the nitrogen atom were investigated in detail, particularly in the following three aspects of the polymerization: (1) N-alkyl1,3-benzoxazines are much more reactive than N-phenyl1,3-benzoxazine. (2) The polymerization rate depended on the bulkiness of the N-substituent The bulkier the substituent was, the slower the polymerization was. (3) The poly-merizations accompanied weight loss due to the elimination of the corresponding imine (R-N = CH2), and its extent became larger when R was more bulky.
- Sudo, Atsushi,Du, Long-Chao,Hirayama, Shoji,Endo, Takeshi
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- Catalyst for curable compositions containing hexahydrotriazine structural units
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A compound containing at least one hexahydrotriazine unit of formula (I) having at least one amidine or guanidine group and to the use thereof as a catalyst for the crosslinking of a functional compound, in particular a polymer including silane groups. The compound contains at least one hexahydrotriazine unit of formula (I) is producible in a simple process from readily available feedstocks, odorless at room temperature, non-volatile and largely non-toxic. The compound accelerates the crosslinking of functional polymers surprisingly well and by simple variation of the substituents is variable such that it has very good compatibility in different polymers as a result of which such compositions do not have a propensity for migration-based defects such as separation, exudation or substrate contamination.
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Page/Page column 34; 35
(2021/08/26)
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- Facile Access to 3-Unsubstituted Tetrahydroisoquinolonic Acids via the Castagnoli-Cushman Reaction
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Hitherto undescribed 3-unsubstituted tetrahydroisoquinolonic acids (isolated as their respective methyl esters) were accessed for the first time by the uncatalyzed, thermally promoted Castagnoli-Cushman reaction (CCR) of homophthalic anhydride (HPA) and a series of 1,3,5-triazinanes. The moderate yields observed in some cases are most likely associated with a persistent impurity also formed in these reactions. The new scaffold is expected to find novel medicinal utility (compared to the traditional CCR adducts) because it lacks a substituent at the 3-position.
- Guranova, Natalia,Dar'In, Dmitry,Krasavin, Mikhail
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p. 2001 - 2008
(2018/03/06)
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- REACTIONS OF DICHLOROMETHANE WITH THIOANIONS. 2. FORMATION OF 5-ALKYL-1,3,5-DITHIAZINANES, 3,5-DIALKYL-1,3,5-THIADIAZINANES, AND 1,3,5-TRIALKYL-1,3,5-TRIAZINANES BY REACTION OF DICHLOROMETHANE WITH SODIUM SULFIDE AND MONOALKYLAMINES
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The reaction of dichloromethane with sodium sulfide and monoalkylamines, catalyzed by polyethyleneglycol 1,500, is studied.A mixture of 5-alkyl-1,3,5-dithiazinane, 3,5-dialkyl-1,3,5-thiadiazinane, and 1,3,5-trialkyl-1,3,5-triazinane is obtained.The proportion of these heterocycles depends on the amine structure and the presence of sodium hydroxide. - Key words: 5-Alkyl-1,3,5-dithiazinanes; 3,5-dialkyl-1,3,5-thiadiazinanes; dichloromethane double substitution; polyethyleneglycol as catalyst
- Torres, Martin,Vega, Juan C.
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p. 125 - 130
(2007/10/03)
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- Alkylation of 6-mercaptopurine (6-MP) with N-alkyl-N-alkoxycarbonylaminomethyl chlorides: S6-(N-alkyl-N-alkoxycarbonyl)aminomethyl-6-MP prodrug structure effect on the dermal delivery of 6-MP
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The S6-(N-alkyl-N-alkoxycarbonyl)aminomethyl-6-MP (6-CARB-6-MP) prodrugs 5-20 were synthesized from the reaction of 6-MP weith N-alkyl-N-alkyoxycarbonylaminomethyl chlorides (4) in dimethyl sulfoxide in overall yields of 5-62%, depending on the N-alkyl and the alkoxy groups involved. The derivatives were fully characterized by spectral and micranalyses. The assignment of the substitution pattern as S6-alkyl was based on comparisons of the UV, 1H NMR and 13C NMR spectra with model compounds. A S6,9-bis-alkyl derivative was obtained from the reaction of 2 equivalents of 4 with 6-MP but the product was unstable and decomposed on standing to a 9-alkyl derivative. The 6-CARB-6-MP prodrugs reverted to 6-MP in water by an S(N)1-type mechanism involving unimolecular charge separation in the transition state of the rate determining step. There was no effect of dermal enzymes on the rate of hydrolysis. The solubilities in isopropyl myristate (IPM) for all of the 6-CARB-6-MP prodrugs were significantly greater than the solubility of 6-MP in IPM but only one prodrug (5) was apparently even as soluble as 6-MP in water. Selected 6-CARB-6-MP prodrugs were examined in diffusion cell experiments. Only the N-methyl-N-methoxycarbonyl derivative 5 gave a steady-state rate of delivery of 6-MP from IPM that was significantly greater than the steady-state rate of delivery of 6-MP from 6-MP in IPM. All the other derivatives gave steady-state rates of delivery of 6-MP from IPM that were either not significantly different, or were significantly lower than the rate obtained from 6-MP in IPM. In all cases, the effect of the 6-CARB-6-MP:IPM suspensions on the permeability of the skin, as determined by the second application flux of theophylline:propylene glycol, was of the same magnitude as the effect of IPM alone.
- Siver,Sloan
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