Reimer

C7H6O2 Oily liquid of aromatic odour b.p. 196°C. (t is prepared by the action of chloroform and caustic potash on phenol (the Reimer-Tiemann reaction) or by the oxidation of the glucoside salicin. It is easily reduced to salicyl alcohol or oxidized to salicylic acid. 

Reimer L 1993 Transmission Electron Microscopy (Berlin Springer)... 

From phenols by interaction with chloroform and sodium hydroxide solution (Reimer - Tiemann reaction), for example ... 

Pinacol-pinacolone rearrangement Prileschajew epoxidation reaction Reformataky reaction Reimer-Tiemanii reaction Rosenmund reduction Sandmeyer reaction Schiemaim reaction Schmidt reaction or rearrangement Schotten-Baumann reaction Skraup reaction Sommelet reaction. ... 

When unsubstituted, C-5 reacts with electrophilic reagents. Thus phosphorus pentachloride chlorinates the ring (36, 235). A hydroxy group in the 2-position activates the ring towards this reaction. 4-Methylthiazole does not react with bromine in chloroform (201, 236), whereas under the same conditions the 2-hydroxy analog reacts (55. 237-239. 557). Activation of C-5 works also for sulfonation (201. 236), nitration (201. 236. 237), Friede 1-Crafts reactions (201, 236, 237, 240-242), and acylation (243). However, iodination fails (201. 236). and the Gatterman or Reimer-Tieman reactions yield only small amounts of 4-methyl-5-carboxy-A-4-thiazoline-2-one. Recent kinetic investigations show that 2-thiazolones are nitrated via a free base mechanism. A 2-oxo substituent increases the rate of nitration at the 5-position by a factor of 9 log... 

Hydroxy-4-methylthiazole failed to react when submitted to Friedel-Crafts benzoylation conditions (349) on the other hand, it reacted normally in Gattermann and in Reimer-Tiemann formylation reactions, affording the 5-formyl derivative (348). 4-Methylthiazole is insufficiently activated and fails to react under the same conditions. 2,4-Dimethylthiazole undergoes perfluoroalkylation when heated at 200° for 8 hr in a sealed tube with perfluoropropyl iodide and sodium acetate (116) (358). 

L. Reimer, ScanningElectron Microscopy, Springer Series in Optical Sciences, Vol. 45, Springer-Vedag Berlin, 1985. 

Pfi2er, Monsanto Sterling, Takeda Haarmann Reimer, Takeda EMC, Monsanto, RhcJ)ne-Poulenc... 

Universal Foods (Wamer-Jenkinson, McCormick/Stange, Kohnstamn), Haarmann Reimer, Hoffmann-La Roche, Colorcon, Quest/Biocon... 

International Flavors and Fragrances, Quest International, Givaudan, Takasago, Haarmann Reimer... 

H. Fiege and co-workers. Proceedings 2nd International Haarmann-Reimer Symposium, 1980, pp. 63—75. 

Although 4-hydroxybenzaldehyde can be made by the saligenin route, it has been made historically by the Reimer-Tiemann process, which also produces sahcylaldehyde (64). Treatment of phenol with chloroform and aqueous sodium hydroxide results in the formation of benzal chlorides, which are rapidly hydrolyzed by the alkaline medium into aldehydes. Acidification of the phenoxides results in the formation of the final products, sahcylaldehyde and 4-hydroxybenzaldehyde. The ratio of ortho and para isomers is flexible and can be controlled within certain limits. The overall reaction scheme is shown in Figure 1. Product separation is accomphshed by distillation, but this process leads to environmental problems because of the quantities of sodium chloride produced. 

Technical data, Haarmaim Reimer Corp., Elkhart, Ind., 1991. 

R. A. Reimer and co-workers, paper presented at the 6th International Workshop on Nitrous Oxide Emissions, Turku/Abo, Finland, June 7—9, 1994, 25... 

Miscellaneous Reactions. The Reimer-Tiemaim reaction of sahcyhc acid (1) with chloroform and alkah (eq. 1) results in the 3- and 5-formyl derivatives. If the reaction is carried out with carbon tetrachloride, the corresponding dicarboxyhc acids form (eq. 2). The products (2) and (3) are 2-hydroxy-l,3-ben2enedicarboxyhc acid [606-19-2] and 4-hydroxy-l,3-ben2enedicarboxyhc acid [636-46-4] respectively. 

In 1874, Tiemann and Ha arm ann examined the stmcture of vanillin and reported it to be 3-methoxy-4-hydroxybenzaldehyde. This was not a difficult task because, on treatment with potassium hydroxide, vanillin (1) gave protocatechaic acid [99-50-3] (2), which, in turn, was decarboxylated to catechol [120-80-9] (3) by dry distillation (eq. 1). As both compounds were known at that time, the position of the substituent groups in vanillin was estabHshed. Finally, Reimer synthesized vanillin from guaiacol [90-05-1] and thus proved the identity of its stmcture. In 1894 RhcJ)ne-Poulenc began producing vanillin on an industrial scale. Since then, many other producers have entered into vanillin production, often only to leave it behind. 

Phenyhsonitrile has a powerful characteristic odor it is used as a qualitative test (the carbylamine test) for chloroform or primary aromatic amines. Chloroform reacts with phenols in alkaline solution to give hydroxyaromatic aldehydes in the Reimer-Tiemann reaction eg, phenol gives chiefly Nhydroxyben2aldehyde and some sahcylaldehyde (11) (see Hydroxybenzaldehydes). 

Economic Aspects. Since the 1970s cinnamaldehyde has been produced in significant quantities by Frit2sche Dodge Olcott (FDO), Haarmaim Reimer (H R), and Dutch State Mines (DSM). However, by the end of 1989 DSM was the only remaining producer for this material. Production statistics are Hsted in Table 3. 

P. W. Staal, Chelation, Technical Bulletin A-1014, Haarmann Reimer Corp., Springfield, N.J., 1989. 

Haarmann Reimer Corp. data 1990 Citric Acid, Chemical Economics Handbook, Stanford Research Institute, Menlo Park, Calif., May 1989. 

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