Reimer-Tiemann Reaction Research Articles

A new type of abnormal reimer-tiemann reaction

The treatment of l, 2, 3, 4, 4a, 9b-hexahydro-3, 8-dihydroxy-7-methoxy-9b-(2'-methoxyethyl)dibenzofuran with chloroform and aqueous potassium hydroxide under conventional Reimer-Tiemann reaction conditions resulted in the replacement of the 7-methoxyl group by a carbaldehyde one. A choice between alternative pathways for this novel displacement has been facilitated by examination of the behaviour of the corresponding 7-trideuteromethoxy compound. Dichlorocarbene attack at position 7 rather than at the unsubstituted position 9 is shown to be due to steric encumbrance at the latter site.

Synthetic approach to diterpene alkaloids: Construction of the bridged azabicyclic ring system of kobusine.

A synthetic study was carried out on the 1-azabicyclo [2.2.1] heptane partial structure (D/E ring system) of an aconite alkaloid, kobusine. A 1-azabicyclo [2.2.1] heptane system, (±)-6, 15, 16-iminopodocarpane-8, 11, 13-triene (3), was synthesized from the 4a-nitromethylhydrophenanthrone (7), which was obtained from the tetrahydrophenanthol (4) through an abnormal Reimer-Tiemann reaction. The bridged nitrogen structure was formed from the bicyclic chloramine (23) by means of the Hofmann-Loffler reaction. The structure of 3 was confirmed by X-ray diffraction analysis.

ChemInform Abstract: A NEW FACET OF THE REIMER‐TIEMANN REACTION

Chemischer InformationsdienstVolume 15, Issue 11 Heterocyclic Compounds ChemInform Abstract: A NEW FACET OF THE REIMER-TIEMANN REACTION C. W. BIRD, C. W. BIRDSearch for more papers by this authorA. L. BROWN, A. L. BROWNSearch for more papers by this author C. W. BIRD, C. W. BIRDSearch for more papers by this authorA. L. BROWN, A. L. BROWNSearch for more papers by this author First published: March 13, 1984 https://doi.org/10.1002/chin.198411181Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume15, Issue11March 13, 1984 RelatedInformation

ChemInform Abstract: THE REIMER‐TIEMANN REACTION

Chemischer InformationsdienstVolume 14, Issue 11 Reviews ChemInform Abstract: THE REIMER-TIEMANN REACTION H. WYNBERG, H. WYNBERGSearch for more papers by this authorE. W. MEIJER, E. W. MEIJERSearch for more papers by this author H. WYNBERG, H. WYNBERGSearch for more papers by this authorE. W. MEIJER, E. W. MEIJERSearch for more papers by this author First published: March 15, 1983 https://doi.org/10.1002/chin.198311348AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume14, Issue11March 15, 1983 RelatedInformation

The effect of phase transfer catalysts on the Reimer-Tiemann reaction

Quaternary ammonium salts were found inactive as phase transfer catalysts in the Reimer-Tiemann reaction. Tertiary amines, on the other hand, proved to have significant effect on the process.

Solvent Effects in the Partition of Phenols as Ion-Pairs with Tetrabutyl Ammonium Cations

Abstract The extraction of phenols as ion-pairs with tetrabutyl ammonium cations was studied with respect to variation of distribution as a function of solvent composition. The large solvent effect observed for 12 phenols gave quantitative agreement with an exponential relationship previously developed for other classes of ion-pairs and had approximately the same magnitude. An exception was noted for phenols substituted at the ortho position by nonpolar groups; decrease of the exponential value in these cases provided support for the controversial concept of specific solvation. Ortho substitution by polar groups led to a pronounced increase of extraction constants; this was explained in terms of delocalization of the anionic charge. Formylation via the Reimer-Tiemann reaction was observed as a complication in the extraction of some of the phenols.

A novel method for angular functionalized methylation via ring opening of bromocyclopropane.

An angular dibromomethyl group was introduced into 1, 1-dimethyl-1, 2, 3, 4-tetrahydrophenanthren-9-ol (I) by the abnormal Reimer-Tiemann reaction using bromoform. I was converted into bromocyclopropane ketone (III), which had a very high reactivity toward various nucleophiles to give the ring-opened products, having angular formyl group IX, XIX, XX and XXVII, cyanomethyl group XII, sulfonylmethyl group XIII, nitromethyl group XIV, thiomethyl group XVII, and iminomethyl group XVIII. These results suggest that this reaction may be a useful method by angular functionalized methylation for the synthesis of natural products.

Tritium nuclear magnetic resonance spectroscopy. Part II. Chemical shifts, referencing, and an application

With the aid of compounds partially monotritiated by base-catalysed exchange with labelled water, corresponding triton and proton chemical shifts measured from internal tritiated water under the same conditions are shown to be the same. Applying this result and using the accurate resonance frequencies of the two nuclei measured at constant field on many of the compounds in organic solvents, a mean value, 1·06663975 (±3 × 10–8), has been obtained for the ratio of the Larmor frequencies, ωT/ωH. This value enables an accurate ghost reference for any 3H n.m.r. spectrum to be derived from the observed 1H n.m.r. frequency of the normal internal reference. The convenience of 3H n.m.r. spectroscopy for solving mechanistic problems is illustrated in respect of the Reimer–Tiemann reaction.

ChemInform Abstract: TROPOLONES AND OTHER PRODUCTS FROM A REIMER‐TIEMANN REACTION

AbstractBei der Reimer‐Tiemann‐Reaktion der Alkylguajacole (I) mit Chloroform‐ NaOH in siedendem wäßrigen Äthanol entstehen neben den zu erwartenden Aldehyden (II) geringe Mengen der Dienone (III) und der Chlortropolone (IV) (letztere vermutlich durch direkte Addition von Dichlorcarben an Phenolatanionen).

Tropolones and other products from a Reimer-Tiemann reaction

The Reimer-Tiemann reaction on 4-methyl-, 4-ethyl-, and 4-propyl- guaiacols gave the corresponding normal 5-alkyl-2-hydroxy-3- methoxybenzaldehydes together with the minor products: 4-alkyl-4- dichloromethyl-2-methoxycyclohexa-2,5-dienones, 4-alkyl-5- chlorotropolones, 3-alkyl-4-chlorobenzoic acids, 6-alkyl-4-hydroxy-3- methoxybenzaldehydes, and 5-alkyltropolones. The minor aldehydes are formed from the dienones during workup by a dienone-phenol rearrangement, and the dienones yield the 5-alkyl-tropolones by the action of alkali. The acids are derived from the chlorotropolones by base-catalysed ring contraction. The chlorotropolones do not appear to be derived from the dienones but rather through direct addition of dichlorocarbene to the phenolate anions.

Relative ease of 1,2-proton shifts. Origin of the formyl proton of salicylaldehyde obtained by the Reimer-Tiemann reaction

Relative ease of 1,2-proton shifts. Origin of the formyl proton of salicylaldehyde obtained by the Reimer-Tiemann reaction

The Reimer-Tiemann Reaction of m-Halophenols. II. With m-Bromophenol

In contrast to results in the literature reported by Hodgson and Jenkinson the Reimer-Tiemann reaction of m-bromophenol yielded four products. Three of these were shown unambiguously to be 2-bromo-4-hydroxybenzaldehyde, 4-, and 6-bromosalicylaldehydes. The other product was assigned to be bromoformylhydroxybenzaldehyde.

Synthesis of organosilicon compounds. XIV. On the reaction of o-(trimethylsilyl)phenol with electrophilic reagents

Reaction of o-(trimethylsilyl)phenol (I) with various electrophilic reagents was examined. Acid and alkali treatment of I results in the severance of silicon-aryl bond and phenol is formed. Bromination of I results in substitution of the position para to the hydroxyl, accompanied by desilylation and p-bromophenol is formed. Coupling reaction of I with benzenediazonium chloride results in the substitution first in the position para to the hydroxyl and then at ortho to form 2-trimethylsilyl-4-(phenylazo)phenol (IV) and then 2-trimethylsilyl-4, 6-bis(phenylazo)phenol (IX), and no further substitution occurs. This is considered to the due to the stabilization of the silicon-aryl bond by the -I effect of the second substitution. Nitration of I with acetyl nitrate at 20° or -50° failed to produce any nitrated product. The Reimer-Tiemann reaction of I gave salicylaldehyde, while the Friedel-Crafts reaction of the methyl ether (XV) of I with aluminum chloride and acetyl or benzoyl chloride afforded p-methoxyacetophenone or p-methoxybenzophenone.

Methylene Derivatives as Intermediates in Polar Reactions. XXIV. The Reimer-Tiemann Reaction with Two p-Substituted Phenols1

Methylene Derivatives as Intermediates in Polar Reactions. XXIV. The Reimer-Tiemann Reaction with Two p-Substituted Phenols¹

324. The reaction of dichloromethylene with water and with phenoxide ions (Reimer–Tiemann reaction)

324. The reaction of dichloromethylene with water and with phenoxide ions (Reimer–Tiemann reaction)

Synthesis of 7-Methyl-8-hydroxyquinoline-5-aldehyde by Reimer-Tiemann Reaction

さきに, 5-メチル-8-オキシキノリンとクロロホルムとを希水酸化ナトリウム水溶液中で反応させたとき,正常な反応生成物であるオキシキノリンアルデヒド誘導体は得られず,ジクロルメチル基が導入された環状ケトンである 8-オキソ-5-メチル-5-ジクロルメチル-5,8-ジヒドロキノリンを得たことを報告した。このような反応は, Reimer-Tiemann 反応の異常反応として,フェノール,ナフトール誘導体については知られていたが,キノリン誘導体としては,はじめて得られたものである。本報では,おなじく活性位である7-位にメチル基をもつ 7-メチル-8-オキシキノリンとクロロホルムの反応について検討した。通常の反応条件に準じて,エタノールを添加した希水酸化ナトリウム水溶液中で反応を行ない,反応溶液を酸性にして生成する沈殿から, mp 179.5°～180.5℃ の黄褐色針状結晶を得た。また, 8-オキソ-5-メチル-5-ジクロルメチル-5,8-ジヒドロキノリンを得る最適条件にしたがって,多量の希水酸化ナトリウム水溶液中で行なった反応でも,反応溶液を酸性にして生成する沈殿から,少量の mp 179.5°～180.5℃ の塩褐色針状結晶を得たが,アルカリ性で反応溶液からクロロホルムに抽出された部分からは,樹脂状物が得られ,予想されたジクロルメチル誘導体を分離確認することができなかった。mp 179.5°～180.5℃ の物質は,フェニルヒドラゾンをつくり,塩化鉄により深緑に呈色する。またメチル基は7-位に存在するから, 5-位に CHO 基が導入された 7-メチル-8-オキシキノリン-5-アルデヒドであって,元素分析値も一致する。

Synthesis of Pyrimidine-5-carboxaldehydes by the Reimer-Tiemann Reaction

Synthesis of Pyrimidine-5-carboxaldehydes by the Reimer-Tiemann Reaction

有機珪素化合物の合成 (第7報)

Various kinds of cationoid reagent were reacted with 3-trimethylsilylphenol (II). Reaction with bromine resulted in primary and secondary substitutions in 4- and 6-positions to afford 3-trimethylsilyl-4-bromophenol and 2, 4-dibromo-5-trimethylsilylphenol. The third substitution occured at either 2- or 3-position and further bromination gave 2, 3, 4, 6-tetrabromophenol. Diazo coupling took place in 4-position and reduction of the azo compound so obtained afforded 3-trimethylsilyl-4-aminophenol. Nitration of the acetate of (II) with acetyl nitrate was difficult. Friedel-Crafts reaction of (II) by application of anhydrous aluminium chloride and acetic anhydride to its methyl ether afforded p-methoxyacetophenone. Fries reaction of (II) by application of anhydrous aluminium chloride to its acetate gave o- and p-hydroxyacetophenone, while Reimer-Tiemann reaction by application of chloroform and potassium hydroxide gave 4-trimethylsilylsalicylaldehyde. Nitrosation with nitrous acid gave 3-trimethylsilyl-4-nitrosophenol and its catalytic reduction afforded the corresponding amine.

Studies on the Reimer-Tiemann Reaction. (Reactions between Chloral Hydrate and Phenols in the. Presence of Caustic Alkali.)

Studies on the Reimer-Tiemann Reaction. (Reactions between Chloral Hydrate and Phenols in the. Presence of Caustic Alkali.)

Polycyclic Compounds. I. The Reimer-Tiemann Reaction with 1-Alkyl-2-naphthols

Polycyclic Compounds. I. The Reimer-Tiemann Reaction with 1-Alkyl-2-naphthols