1,3-Dimethyl-5,6-dihydrothymine | 19274-22-7

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 二嗪类
• 英文名称: 1,3-Dimethyl-5,6-dihydrothymine
• 英文别名: 1,3,5-trimethyl-dihydro-pyrimidine-2,4-dione；1,3,5-trimethyl-1,3-diazinane-2,4-dione
• CAS: 19274-22-7
• 化学式: C₇H₁₂N₂O₂
• 分子量: 156.184
• InChiKey: VWTYZDMKFMFQIY-UHFFFAOYSA-N

物化性质

• 沸点：
  216.2±23.0 °C(Predicted)
• 密度：
  1.103±0.06 g/cm3(Predicted)

计算性质

• 辛醇/水分配系数(LogP)：
  -0.2
• 重原子数：
  11
• 可旋转键数：
  0
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.71
• 拓扑面积：
  40.6
• 氢给体数：
  0
• 氢受体数：
  2

反应信息

• 作为反应物：
  描述：

  1,3-Dimethyl-5,6-dihydrothymine 生成 1,3-二甲基尿嘧啶-5-甲醛
  参考文献：
  名称：

  ITAHARA, TOSHIO;IDE, NAOKO, MED., BIOCHEM. AND CHEM. ASPECTS FREE RADICALS: PROC. 4TH BIENN. GEN. MEE+

  摘要：

  DOI：
• 作为产物：
  描述：

  1,3-二甲基胸腺嘧啶 在 氢气 作用下， 生成 1,3-Dimethyl-5,6-dihydrothymine
  参考文献：
  名称：

  转移氢化作为核苷酸中的氧化还原过程

  摘要：

  使用理论和实验相结合的策略，已确定了核苷酸碱基尿嘧啶，胸腺嘧啶，胞嘧啶，腺嘌呤和鸟嘌呤的氢化热。最容易氢化的碱基是尿嘧啶，其次是胸腺嘧啶和胞嘧啶。这些氢化焓与糖模型衍生的酮和醛的氢化焓的比较表明，寡核苷酸中尿嘧啶和糖磷酸主链之间存在近乎中性的氢转移。

  DOI：

  10.1021/jp507855k

文献信息

• A new synthesis of n-blocked dihydrouracil and dihydroorotic acid derivatives using lithium tri-sec-butyl borohydride as reducing agent
  作者：Stephen J. Hannon、Nitya G. Kundu、Robert P. Hertzberg、Ram S. Bhatt、Charles Heidelberger

  DOI：10.1016/s0040-4039(01)83925-3

  日期：——

  1,3-Di-N-substituted uracil and its derivatives have been reduced with lithium-tri-sec-butyl borohydride to the corresponding 5,6-dihydro compounds in excellent yields. Alkylation of 5-position of uracil is also very conveniently accomplished.

  用三仲丁基硼氢化锂将1，3-二-N-取代的尿嘧啶及其衍生物还原成相应的5，6-二氢化合物，产率极高。尿嘧啶5-位的烷基化也很方便地完成。
• Stereoisomeric C5−C5‘-Linked Dihydrothymine Dimers Produced by Radiolytic One-Electron Reduction of Thymine Derivatives in Anoxic Aqueous Solution:  Structural Characteristics in Reference to Cyclobutane Photodimers
  作者：Takeo Ito、Hideki Shinohara、Hiroshi Hatta、Sei-ichi Nishimoto

  DOI：10.1021/jo990059s

  日期：1999.7.1

  Radiolytic one-electron reduction of 1-methylthymine (1a) and 1,3-dimethylthymine (1b) in anoxic aqueous solution afforded stereoisomeric C5-C5'-linked dihydrothymine dimers, fractionated into the meso forms of (5R,5'S)- and (5S,5'R)-bi-5,6-dihydrothymine (3a,b[meso]) and a racemic mixture of (5R,5'R)- and (5S,5'S)-bi-5,6-dihydrothymines (3a,b[rac]), along with 5,6-dihydrothymines (2a,b). The meso

  1-甲基胸腺嘧啶 (1a) 和 1,3-二甲基胸腺嘧啶 (1b) 在缺氧水溶液中的辐射单电子还原得到立体异构的 C5-C5'-连接的二氢胸腺嘧啶二聚体，分馏成 (5R,5'S)- 和 ( 5S,5'R)-bi-5,6-dihydrothymine (3a,b[meso]) 和 (5R,5'R)- 和 (5S,5'S)-bi-5,6-dihydrothymines 的外消旋混合物（ 3a,b[rac])，以及 5,6-二氢胸腺嘧啶 (2a,b)。内消旋和外消旋二聚体的产量几乎相等，与顺式-syn-环丁烷嘧啶光二聚体具有结构相似性，顺式-syn-环丁烷嘧啶光二聚体被确定为紫外线诱导的高度诱变和致癌光损伤。胸苷 (1c) 的类似辐射解单电子还原导致 (5R,5'S)- 和 (5S,5'R)-bi-5,6-二氢胸苷 (3c[RS]) 和两种非对映异构体的拟内消旋形式(5R,5' R)-和 (5S,5'S)-双-5
• Protonation of the Electron Adducts of Pyrimidine Derivatives.
  作者：Kazue OHKURA、Koh-ichi SEKI

  DOI：10.1248/cpb.43.1024

  日期：——

  Photolyses of 5-substituted 1, 3-dimethyluracils (1a-e : a, R=F; b, R=Cl; c, R=H; d, R=CH3; e, R=p-xylyl) in p-xylene in the presence of trifluoroacetic acid (TFA) afforded 5, 6-dihydro-1, 3-dimethyl-6-p-methylbenzyluracils (3a-d), 5, 6-dihydro-1, 3-dimethyl-5-p-methylbenzyluracils (4a-e), and 5, 6-dihydro-1, 3-dimethyluracils (5a-e) in varying ratios. It is suggested that the 6-isomers (3) are derived from the O(4)-protonated electron adducts of 1, while 4 and 5 are the products from the C(6)-protonated electron adducts. The ratio of (4+5) vs. 3 depends on the ionization potentials of the O(4)-protonated intermediates. The formation of 4+5 increases with increasing concentration of TFA.

  5 取代的 1，3-二甲基尿嘧啶（1a-e ：a, R=F; b, R=Cl; c, R=H; d, R=CH3；e, R=p-xylyl) 在对二甲苯中，在三氟乙酸 (TFA) 的存在下，以不同的比例得到 5, 6-二氢-1, 3-二甲基-6-对甲基苄基尿嘧啶 (3a-d)、5, 6-二氢-1, 3-二甲基-5-对甲基苄基尿嘧啶 (4a-e) 和 5, 6-二氢-1, 3-二甲基尿嘧啶 (5a-e)。据认为，6-异构体（3）来自于 1 的 O（4）-质子化电子加合物，而 4 和 5 则是 C（6）-质子化电子加合物的产物。(4+5) 与 3 的比例取决于 O(4)-质子化中间产物的电离电位。4+5 的形成随着反式脂肪酸浓度的增加而增加。
• Photoinduced Electron Transfer to Pyrimidines and 5,6-Dihydropyrimidine Derivatives:  Reduction Potentials Determined by Fluorescence Quenching Kinetics
  作者：Michael P. Scannell、Gautam Prakash、Daniel E. Falvey

  DOI：10.1021/jp970164a

  日期：1997.6.1

  The dynamics of flourescence quenching of excited state electron donor sensitizers by various pyrimidine and 5,6-dihydropyrimidine substrates was examined. For all of the substrates studied the rate constant of fluorescence quenching (k(q)) increases as the excited state oxidation potential (E-ox*) becomes more negative. The dependence of k(q) on E-ox* in each case is well described by the Rehm-Weller relationship. Fits of the data to this relationship allow for the estimation of the reduction potentials of the substrates (E-red) The pyrimidines 1,3-dimethylthymine, 1,3-dimethyluracil, and 1,3,6-trimethyluracil give E-red values (in CH3CN) ranging from -2.06 (vs SCE) to -2.14 V. Their dihydro derivatives, 1,3-dimethyl-5,6-dihydrothymine, 1,3-dimethyl-5,6-dihydrouracil, and 1,3,6-trimethyl-5,6-dihydrouracil gave E-red values ranging from -1.90 to -2.07 V. The higher E-red values for the dihydropyrimidines compared with their unsaturated derivatives is attributed to aromatic stabilization in the pyrimidines, which is not present in the dihydro derivatives. In addition, the E-red for both the trans-syn and cis-syn diastereomers of the dimethylthymine cyclobutane dimer was examined using the same method. The trans-syn dimer gives an E-red Of -1.73 V and the cis-syn dimer gives an E-red Of -2.20 V. This remarkable difference is attributed to a stereoelectronic effect. The cis-syn dimer anion radical suffers from an unfavorable charge-dipole interaction between the added electron and the O-4 carbonyl group in the remaining pyrimidine ring. In contrast, the trans-syn dimer anion radical shows mainly a stabilizing inductive electron-withdrawing effect of the remaining O-4 carbonyl group. Solvent effects on E-red were also examined. It is shown that the protic solvent, CH3OH, significantly stabilizes the anion radicals, raising E-red by ca. 400 mV over the value in CH3CN.
• Radiation-Induced and Photosensitized Splitting of C5−C5‘-Linked Dihydrothymine Dimers:  Product and Laser Flash Photolysis Studies on the Oxidative Splitting Mechanism
  作者：Takeo Ito、Hideki Shinohara、Hiroshi Hatta、Sei-ichi Nishimoto、Shin-ichi Fujita

  DOI：10.1021/jp991877r

  日期：1999.10.1

  Radiation-induced and photosensitized one-electron oxidation of stereoisomeric CS-CS'-linked dihydrothymine dimers (1a,b[meso], meso compound of (5R,5'S)-bi-5,6-dihydrothymine; la,b[rac], racemic compound of (5R,5'R)- and (5S,5'S)-bi-5,6-dihydrothymines), which are the major products yielded by radiolytic reduction of 1-methylthymine (2a) and 1,3-dimethylthymine (2b) in aqueous solution, was studied to compare with the photoreactivating repair mechanism of cyclobutane pyrimidine photodimers. Reacting with sulfate radical anion (SO4.-), azide radical (N-3(.)), Or photoexcited anthraquinone-2-sulfonate (AQS) as oxidants, the C5-C5'-linked dihydrothymine dimers la,b split to regenerate the corresponding thymine monomers 2a,b along with 5,6-dihydrothymines (3a,b) in a pH dependent manner. The transient absorption spectra of 5,6-dihydrothymin-5-yl radicals (6a,b) were observed in the nanosecond laser flash photolysis of 1a,b in phosphate buffer under conditions of SO4.- generation. Both the product study and the laser flash photolysis study indicated an oxidative splitting mechanism by which one-electron oxidation of the C5-C5'-linked dimers la,b produces the radical cation intermediates (4a,b), which undergo facile fragmentation into 5,6-dihydrothymin-5-yl radicals 6a,b and CS-cations (5a,b), followed by deprotonation at C6 of 5a,b to regenerate the monomers 2a,b.