2,3,5,6-tetramethylanisole | 14337-37-2

• 分子结构分类: 有机化合物 - 苯类化合物 - 苯酚醚
• 英文名称: 2,3,5,6-tetramethylanisole
• 英文别名: methyl ether of durenol；2,3,5,6-tetramethyl-anisole；2,3,5,6-Tetramethyl-anisol；2,3,5,6-Tetramethyl-phenol-methylether；4-Methoxy-2,3,5,6-tetramethyl-benzol；3-Methoxy-1,2,4,5-tetramethylbenzene
• CAS: 14337-37-2
• 化学式: C₁₁H₁₆O
• 分子量: 164.247
• InChiKey: VEVHOGLUQUBJBW-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  3.4
• 重原子数：
  12
• 可旋转键数：
  1
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.45
• 拓扑面积：
  9.2
• 氢给体数：
  0
• 氢受体数：
  1

反应信息

• 作为反应物：
  描述：

  2,3,5,6-tetramethylanisole 在 硫酸 作用下， 生成 4-Methoxymethyl-2,3,5,6-tetramethylanisol
  参考文献：
  名称：

  芳烃与侯爵试剂反应机理的研究

  摘要：

  2,3,5,6-四甲基-N, N-二甲基苄胺 (I)、甲氧基杜醇 (II) 和杜伦醇 (III) 与 Marquis 试剂的反应表明，仅碳正离子是颜色形成的原因。这是通过在低温核共振光谱的帮助下确定碳正离子的结构以及通过分离确定的反应产物以化学方式直接完成的。简要概述了酚类反应类型的特殊性。

  DOI：

  10.1002/ardp.19743071208
• 作为产物：
  描述：

  2,6-bis(hydroxymethyl)-3,5-dimethylanisole 在 5%-palladium/activated carbon 、 氢气 作用下， 以 甲醇 为溶剂， 反应 8.0h， 以55%的产率得到2,3,5,6-tetramethylanisole
  参考文献：
  名称：

  Syntheses of extreme sterically hindered 4-methoxyboronic acids

  摘要：

  4-Iodoanisoles 3a,b, 3d and 4-bromoanisoles 4a-d were readily obtained. An extreme steric hindrance precluded obtaining 3c. Catalytic borylation of 3a,b, 3d followed by hydrolysis of boronic ester 26a,b, 26d easily provided the boronic acids 5a,b, 5d. Compounds Sa and 5d were also synthesised, starting from 4a and 4d, by halogen/metal exchange. Because of a too important steric hindrance, this last reaction failed with 4c and 4b led to the unexpected but stable boronic ester 6. The final obtaining of 5b required a strongly basic hydrolysis with heating. (C) 2009 Elsevier Ltd. All rights reserved.

  DOI：

  10.1016/j.tet.2009.11.103

文献信息

• Method for protecting guanidino group and restoring the same
  申请人：Takeda Chemical Industries, Ltd.

  公开号：US04368150A1

  公开（公告）日：1983-01-11

  A guanidino group in an amino acid or a peptide can be protected with a specific group, i.e. pentamethylbenzensulfonyl, 2,4,6-trimethoxybenzenesulfonyl, 4-methoxy-2,3,5,6-tetramethylbenzenesulfonyl, 4-methoxy-2,6-dimethylbenzenesulfonyl or 4-methoxy-2,3,6-trimethylbenzenesulfonyl, and said group may easily be removed without affecting the amino acid or the peptide to be derived from the protected amino acid or peptide. Thus, the present invention is useful in the synthesis of peptides containing the guanidino group.

  氨基酸或肽中的胍基团可以用特定的基团进行保护，即五甲基苯磺酰基，2,4,6-三甲氧基苯磺酰基，4-甲氧基-2,3,5,6-四甲基苯磺酰基，4-甲氧基-2,6-二甲基苯磺酰基或4-甲氧基-2,3,6-三甲基苯磺酰基，并且该基团可以在不影响从受保护的氨基酸或肽衍生的氨基酸或肽的情况下轻松去除。因此，本发明在合成含有胍基团的肽方面是有用的。
• Trifluoroacetic acid-catalysed transacylation of arenes by acylpentamethylbenzene
  作者：Takashi Keumi、Toshio Morita、Takanobu Shimada、Naomi Teshima、Hidehiko Kitajima、G. K. Surya Prakash

  DOI：10.1039/p29860000847

  日期：——

  by the mixed anhydride. The mechanism resulting in an ipso-protonated intermediate B was deduced from the reaction of acetylmesitylene with [2H]TFA as well as from the rate of deacetylation of 3,5-dideuterioacetylmesitylene with TFA. The formation of such an intermediate was also independently confirmed by 13C n.m.r. spectroscopic studies on AcPMB in superacid solutions under stable ion conditions.

  发现在沸腾的三氟乙酸（TFA）中发生酰基戊二甲基苯与活化的芳烃（如苯甲醚）之间的容易的转酰基作用。通过产物分离和动力学阐明了乙酰戊五甲基苯（AcPMB）和苯甲醚与TFA的转酰化机理。该反应进行经由AcPMB的可逆protodeacetylation涉及的本位-protonated中间体B，得到五甲基苯和乙三氟乙酸酐，接着通过混合酸酐苯甲醚不可逆乙酰化。从而导致该机构本位-protonated中间体B由acetylmesitylene与[反应推导2H] TFA以及3,5-二氘代乙酰基乙酰间苯三甲与TFA的脱乙酰速率。这种中间体的形成还通过在稳定离子条件下在超酸溶液中对AcPMB的13 C nmr光谱研究独立地证实。
• The dechlorination of some highly chlorinated naphthalene derivatives
  作者：Neil J Hales、Harry Heaney、John H Hollinshead、Steven Mf Lai、Pritpal Singh

  DOI：10.1016/0040-4020(95)00396-p

  日期：1995.7

  The [4+2]cycloadducts formed between tetrachlorobenzyne and a variety of arenes and cyclic 1,3-dienes have been reductively dechlorinated. The products are formally benzyne cycloadducts, many of which are difficult to make by other routes. High yields are obtained when sodium and t-butanol in boiling THF are used for the reduction. THF serves as a solvent but t-butanol not only acts as a proton donor

  在四氯苯并与各种芳烃和环状1,3-二烯之间形成的[4 + 2]环加合物已被还原脱氯。该产品是正式的苯并环加合物，其中许多很难通过其他途径制备。当使用沸腾的THF中的钠和叔丁醇进行还原时，可获得高收率。THF用作溶剂，但叔丁醇不仅充当质子供体，而且似乎开始还原。每当需要苯并本身时，就应考虑将四氯苯甲酮视为替代试剂。
• [EN] PROCESS FOR PREPARATION OF ACITRETIN<br/>[FR] PROCÉDÉ DE PRÉPARATION D'ACITRÉTINE
  申请人：EMCURE PHARMACEUTICALS LTD

  公开号：WO2016042573A1

  公开（公告）日：2016-03-24

  The present invention provides a process for preparation of (2E,4E,6E,8E)-9-(4-methoxy-2,3,6- trimethyl)phenyl-3,7-dimethyl-nona-2,4,6,8}tetraenoate, an acitretin intermediate of formula (VI) with trans isomer ≥97%, comprising of reacting 3-formyl-crotonic acid butyl ester of formula (V), substantially free of impurities, with 5-(4-methoxy-2,3,6-trimethylphenyl)-3- methyl-penta-2,4-diene-l-triphenyl phosphonium bromide of formula (IV) and isolating resultant compound of formula (VI), treating the filtrate with iodine for isomerization of the undesired cis intermediate and finally obtaining acitretin (I), with desired trans isomer ≥97%.

  本发明提供了一种制备(2E,4E,6E,8E)-9-(4-甲氧基-2,3,6- 三甲基)苯基-3,7-二甲基-壬二烯酸酯，即式（VI）的乙酸类似物的过程，其反应物为式（V）的3-甲酰基-巴比妥酸酯，基本无杂质，与式（IV）的5-(4-甲氧基-2,3,6-三甲基苯基)-3-甲基-戊二烯-1-三苯基磷溴化铵反应，并分离产物（VI）的化合物，用碘处理滤液以异构化不需要的顺式中间体，最终获得乙酸类似物（I），其所需的顺式异构体≥97%。
• Stable carbonium ions. XLV. Benzyl cations
  作者：J. Martin. Bollinger、Melvin B. Comisarow、Chris A. Cupas、George A. Olah

  DOI：10.1021/ja00998a034

  日期：1967.10

  benzyl cations were prepared by careful addition of the corresponding benzyl chlorides to well-stirred SbF,-S02 solutions at -75°. Introduction of alkyl substituents not only impede side reactions such as alkylation, but also further increase the stability of the benzyl cation inductively. (1) Part XLIV: G. A. Olah, M. Calin, and D. H. O'Brien, J. Am. Chem. Soc., 89, 3591 (1967); for a preliminary communication

  通过在-60° SbF,-SO, 溶液中电离相应的苄基氯，获得了一系列环取代的苄基阳离子（苯基碳鎓离子）。研究了离子的核磁共振和紫外光谱。2,6-二取代苄基阳离子的孪生质子-质子磁共振耦合常数以及碳-氢耦合进一步证明了碳正离子的平面 sp' 杂化性质。迄今为止，在苄基阳离子溶液中产生和观察光谱特性的各种尝试均未成功。1-4 电离后对苄基阳离子开放的进一步反应途径，例如分子间烷基化，无疑是 conCH，“Y -CH5 归功于其明显的不稳定性。结果和讨论使用我们之前研究中开发的方法观察稳定，长寿命碳正离子在溶液中，我们能够观察到苄基阳离子 I-VI、VIII、XI、XII 和 XIV。这些苄基阳离子是通过在 -75° 下将相应的苄基氯小心添加到充分搅拌的 SbF,-SO 2 溶液中来制备的。烷基取代基的引入不仅可以阻止烷基化等副反应，而且还可以进一步提高苄基阳离子的稳定性。(1) 第 XLIV