6-Bromo-2-naphthol, reaction with

In the reaction with 6-bromo-2-naphthol, no simple glycosides were obtained, but a mixture of tetracyclic compounds in yields of 32 % and 44 %, respectively (zirconocene activator). The hafnium reagent gave the same products in a similar ratio (21% and 44% yield) [30]. 

Bromo-2-naphthol is a source of 8-hydroxynaphtho[2,l-6]pyrans from which pyrano[3,2- ]naphtho[2,l-6]pyrans are formed on reaction with a 1,1-diarylprop-2-yn-l-ol. These molecules absorb at ca. 390 nm in the UV and at ca. 490 nm following irradiation <95USP5674432>. 

For fast reactions of the type represented by reaction 13.2, carried out under the conditions stated earlier, micromixing becomes the dominant consideration. However, studies on the effect of micromixing in such reactions are sparse. Some examples are as follows nitration of aromatic componds in general (Schofield, 1980), potassium metal-provoked reactions of aryl halides with amide and acetone enolate ions (Tremelling and Bunnett, 1980X coupling of 1-naphthol with diazotized sulfanilic acid (Bourne et al., 1981, 1985), reactions of o-(3-butenyl)-halobenzenes and 6-bromo-1-hexene with alkali metals in ammonia/terr-butyl alcohol solution (Meijs et al., 1986), and monoacylation of symmetrical diamines (Jacobson et al., 1987). In some fast reactions, hydrogen ions are produced. 

In their seminal work published in 1999, Uang and co-workers demonstrated the potential of using inexpensive and stable oxovanadium(iv) complex VO(acac)2 to catalyze oxidative coupling reactions of 2-naphthols (Table 3.5). Molecular oxygen was identified as an efficient terminal oxidant. A bromo or methoxyl substituent was tolerated on the naphthalene ring (entries 2 and 3), but the reaction with the substrate bearing an ester... 

Further application of this practical synthetic approach has been performed by the coupling reaction with different types of alcohols. 2-Methoxy-5-bro-mobenzyl alcohol and 6-bromo-2-naphthol were nicely coupled with P7 under the reaction conditions given in Scheme 3.12, resulting in the coupling products... 

An unusual domino process was observed by Biehl and coworkers [69] in the reaction of 2-bromo-l-naphthol 4-196 with arylacetonitriles in the presence of LDA or LiTMP by employing 3-thienylacetonitrile 4-197, the tetracyclic compound 4-200 was obtained in 57% yield (Scheme 4.43). The reaction probably includes the formation of an aryne and a ketenimine which undergo [2+2] cycloaddition to give 4-198, followed by rearrangement and allylic addition to the intermediately formed aryl cyano compound 4-199. 

Enals and enones as well as ketones react with orfho-functionalized bromo-benzenes to give the corresponding cyclized products (cf. Eqs. 22-24). The reaction of o-dibromobenzenes with alkenals gives benzocyclobutane derivatives (Eq. 29) [61]. 1-Naphthol derivatives are produced by using o-bromobenzalde-... 

To evaluate whether our experimental system can detect the contribution of a direct reaction, we substituted the highly charged emitter with the neutral one, 0-naphthol. The protonation cycle of Bromo Cresol Green, in the presence of 0-naphthol, is depicted in Figure 30. Calculations that did not account for the contribution of the direct proton exchange (reaction 31) gave unsatisfactory simulations. However, including the rate constants of reaction (30) in the differential rate equations... 

Figure 31. The effect of pH on the response of Bromo Cresol Purple during the proton pulse. The reaction mixture contained Bromo Cresol Purple (lOOpAf) and P-naphthol (ImAf) at pH 7.05 (A) and 5.12 (B). Each tracing is an average of 4096 events. Downward deflection corresponds with protonation of indicator.

Reaction of 2-fluoroglycosyl fluoride 148 with 6-bromo-2-naphthol with Cp2HfCl2-AgOTf catalysis affords the fused carbohydrate-containing tetracycles 149 and 150 in 44% and 21% yields respectively. Similar chemistry was applied to phenol derivatives. ... 

In addition to the examples discussed above, arynes have also been found to insert into C-C single bonds. The reaction of either 2- or 3-bromophenol with arylacetonitriles in the presence of a strong base, such as lithium 2,2,6,6-tetramethylpiperidide (LiTMP), led to the same major products, 2-arylmethyl-6-hydroxybenzenecarbonitriles 23 (Scheme 12.9) [26]. In both cases, lithium 2,3-didehydrophenoxide (21) was generated. The anion of nitrile 20 then adds solely at the 3-position of 21 to afford adduct 22, which subsequently leads to the final product 23 after intramolecular rearrangement. When 2-bromo-l-naphthol was used instead of 2-bromophenol, a similar reachvity was observed [27]. 

Aromatic amines can sometimes be chromatographed successfuly after their conversion to derivatives. For example, isomeric toluidines and aniline, which are poorly separated as salts, can be clearly separated after their conversion to bromo derivatives (105) a series of primary amines can be separated after conversion to arylazo-2-naphthole (p. 342), and for the separation of isomers the products of the reaction of amines with diazonium salts (p. 324) can also be employed. They can be chromatographed in a formamide/hexane system. Thin-layer chromatography of free bases can be carried out on nonadhering layers of alumina (106, 107), or on silica gel G layers using the mobile phase cyclohexane — carbon tetrachloride-ethyl ecetate (10 70 20) ... 

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