Isopropyl alcohol, alkylation with

Mg or Ca in MeOH, " baker s yeast, Sm/l2, LiMe2NBH3, and tin complexes prepared from SnCl2 or Sn(SR)2. This reaction, combined with RX —+ RN3 (10-65), is an important way of converting alkyl halides RX to primary amines RNH2 in some cases the two procedures have been combined into one laboratory step. Sulfonyl azides (RSO2N3) have been reduced to sulfonamides (RSO2NH2) by irradiation in isopropyl alcohol and with NaH. ... 

Mix 40 g. (51 ml.) of isopropyl alcohol with 460 g. (310 ml.) of constant boiling point hydrobromic acid in a 500 ml. distilling flask, attach a double surface (or long Liebig) condenser and distil slowly (1-2 drops per second) until about half of the liquid has passed over. Separate the lower alkyl bromide layer (70 g.), and redistil the aqueous layer when a further 7 g. of the crude bromide will be obtained (1). Shake the crude bromide in a separatory funnel successively with an equal volume of concentrated hydrochloric acid (2), water, 5 per cent, sodium bicarbonate solution, and water, and dry with anhydrous calcium chloride. Distil from a 100 ml. flask the isopropyl bromide passes over constantly at 59°. The yield is 66 g. 

Diisopropjibenzenes (DIPB) are readily obtained via Eriedel-Crafts alkylation of benzene or cumene by propylene. This reaction inhquid phase has not evolved drastically since 1980 with the exception of the large variety of heterogeneous acid catalysts that are now being used, mainly zeoHtes, type HZSM-12, giving a para/meta ratio = 0.7 (4). In fact, propylene can also be replaced by isopropyl alcohol coming from the hydrogenation of acetone that... 

Acidic ether cleavages are typical nucleophilic substitution reactions, either SN1 or Sn2 depending on the structure of the substrate. Ethers with only primary and secondary alkyl groups react by an S 2 mechanism, in which or Br attacks the protonated ether at the less hindered site. This usually results in a selective cleavage into a single alcohol and a single alkyl halide. For example, ethyl isopropyl ether yields exclusively isopropyl alcohol and iodoethane on cleavage by HI because nucleophilic attack by iodide ion occurs at the less hindered primary site rather than at the more hindered secondary site. 

The dimerization of ketones to 1,2-diols can also be accomplished photochemi-cally indeed, this is one of the most common photochemical reactions. The substrate, which is usually a diaryl or aryl alkyl ketone (though a few aromatic aldehydes and dialkyl ketones have been dimerized), is irradiated with UV light in the presence of a hydrogen donor such as isopropyl alcohol, toluene, or an amine. In the case of benzophenone, irradiated in the presence of 2-propanol, the ketone molecule initially undergoes n — k excitation, and the singlet species thus formed crosses to the T, state with a very high efficiency. 

The objective of this contribution is to investigate catalytic properties of zeolites differing in their channel systems in transformation of aromatics, i.e. toluene alkylation with isopropyl alcohol and toluene disproportionation. In the former case zeolite structure and acidity is related to the toluene conversion, selectivity to p-cymene, sum of cymenes, and isopropyl/n-propyl toluene ratio. In the latter one zeolite properties are... 

The catalytic activity of SSZ-33 and SSZ-35 was compared with those of ZSM-5 and Beta in toluene disproportionation and toluene alkylation with isopropyl alcohol. The crystals size of SSZ-33 and Beta is about 0.2-0.3 pm while crystals of ZSM-5 and SSZ-35 are larger - around 1 pm. Thus, the size of all crystals provides a nice opportunity to compare the catalytic behavior of zeolites in toluene transformations. 

Figure 2 Dependence of toluene conversion and selectivity to p-cymene in toluene alkylation with isopropyl alcohol.

Toluene alkylation with isopropyl alcohol was chosen as the test reaction as we can follow in a detail the effect of zeolite structural parameters on the toluene conversion, selectivity to cymenes, selectivity to para-cymene, and isopropyl/n-propyl ratio. It should be stressed that toluene/isopropyl alcohol molar ratio used in the feed was 9.6, which indicates the theoretical toluene conversion around 10.4 %. As you can see from Fig. 2 conversion of toluene over SSZ-33 after 15 min of T-O-S is 21 %, which is almost two times higher than the theoretical toluene conversion for alkylation reaction. The value of toluene conversion over SSZ-33 is influenced by a high rate of toluene disproportionation. About 50 % of toluene converted is transformed into benzene and xylenes. Toluene conversion over zeolites Beta and SSZ-35 is around 12 %, which is due to a much smaller contribution of toluene disproportionation to the overall toluene conversion. A slight increase in toluene conversion over ZSM-5 zeolite is connected with the fact that desorption and transport of products in toluene alkylation with isopropyl alcohol is the rate controlling step of this reaction [9]... 

In toluene disproportionation the highest toluene conversion was achieved over SSZ-33 due to a high acidity combined with 3-D channel system. High toluene conversion over SSZ-35 results from its strong acidity and large reaction volumes in 18-MR cavities. Toluene conversion in the alkylation with isopropyl alcohol is influenced by a high rate of competitive toluene disproportionation over SSZ-33. ZSM-5 exhibits a high p-selectivity for /7-isopropyl toluene, which seems to be connected with diffusion constraints in the channel system of this zeolite. 

Catalysts described in the literature and in patents contain Pd(OAc)2 and PR3 (R = alkyl and aryl). Short-chained alcohols (Ci to C4) are typically used as nucleophiles (Scheme 3) and at reaction conditions of 120 °C, 50 bar CO and 15 hours, the desired linear (isopropyl-)nonadienoate is formed as the main product with isopropyl alcohol (IPA) as the alcohol component. 

Diaryl ketones do not undergo photodissociation in the same way as alkyl ketones, probably because cleavage to phenyl and other aryl radicals is unfavorable (Table 4-6). Nevertheless, aromatic ketones are photochemically reactive in the presence of compounds that can donate a hydrogen atom, with the result that the carbonyl group is reduced. Indeed, one of the classic photochemical reactions of organic chemistry is the formation of 1,1,2,2-tetraphenyl-1,2-ethanediol (3, benzopinacol) by the action of light on a solution of diphenyl-methanone (2, benzophenone) in isopropyl alcohol. The yield is quantitative. 

Friedel-Crafts alkylation of benzo[6]thiophene has received little attention. The published results, which deserve reexamination, indicate that exclusive 3-substitution occurs in some cases, whereas in others, 2-substitution predominates. Benzo[6]thiophene is alkylated with isopropyl chloride, isopropanol, or propene in the presence of various acid catalysts under a variety of reaction conditions to give a mixture of 2- and 3-isopropylbenzo[6]thiophene in which the 2-isomer predominates (78-92%).358 410 In contrast, alkylation with isobutene in the presence of either 80% sulfuric acid415 or 100% phosphoric acid416 is said to afford exclusively 3-/er<-butylbenzo[6]thiophene in yields of 100 and 75%, respectively. In neither case was the structure of the product rigorously confirmed. Likewise, 3-Jeri-amylbenzo [63-thiophene is the exclusive product of alkylation with tert-amyl alcohol in the presence of stannic chloride414 alkylation with pent-l-ene, hex-l-ene, and a Ci8 propylene polymer is also claimed to give... 

Recall that alkyl substituents on the double bond increase the reactivity of alkenes toward electrophilic addition. Propene therefore reacts faster than ethylene with sulfuric acid, and the mixture of alkyl hydrogen sulfates is mainly isopropyl hydrogen sulfate, and the alcohol obtained on hydrolysis is isopropyl alcohol. 

Isopropyl anisole (171) was converted to bromide (172) by metalation, formylation and bromination. Alkylation with cyclopropyl ketoester produced (173) whose transformation to alcohol (174) was achieved by saponification, decarboxylation and reduction.. Its conversion to homoallylic bromide (175) was accomplished by the method of Julia et al. [56]. Alkylation of ethyl acetoacetate with bromide (175) furnished p-ketoester (176). It was subjected to cyclization with stannic chloride in dichloromethane. The resulting tricyclic alcohol provided the olefinic ester (177) by treatment with mesylchloride and triethylamine. Epoxidation followed by elimination led to the previously reported intermediate (146) whose conversion to triptolide (149) has already been described. 

Alcohols are compounds that contain a hydroxy group (—OH). Common names for simple alcohols use the name of the alkyl group followed by alcohol, such as ethyl alcohol or isopropyl alcohol. In the IUPAC system, alcohols are given the name of the hydrocarbon from which they are derived, with the suffix -ol replacing the final e of the name. The longest chain that contains the carbon bonded to the hydroxy group is chosen as the root and numbered so that this carbon has the lowest possible number. 

---