Sec Butyl fluoride

The same strategy may be employed for calculating the enthalpy of formation for sec-butyl fluoride. The set of assumptions now used are the equality of equation 9... 

Normal olefins in the feedstreams react to a considerable extent with either sulfuric acid or HF, forming either isoalkyl sulfate esters or isoalkyl fluorides, respectively (13,14). With either 1-butene or 2-butenes, both sec-butyl acid sulfate and di-sec-butyl sulfate are obtained when sulfuric acid is employed. The isoalkyl acid sulfate dissolves mainly in the sulfuric acid, and the neutral sulfate dissolves mainly in the hydrocarbon phase (14,15). sec-Butyl fluoride is the reaction product of re-butenes and HF. Both 2-pentyl and 3-pentyl sulfates and fluorides are produced when re-pentenes are feedstocks. There is no known evidence that either isobutylene or isopentenes give stable sulfates or fluorides during alkylation. 

Although no specific analysis was made to Identify sec-butyl sulfate in the acid phase, there seems little doubt that this sulfate was the reaction product obtained in the n-butene runs. First, the n-butenes and acid reacted on essentially a 1 1 molar basis only a slight excess of acid was needed In all cases. Of Interest, formation of butyl sulfates has also been reported to occur In conventional alkylation reactors (13). Second, the reaction product was similar 1n many respects as compared to sec-propyl sulfate the product was unstable at higher temperatures and 1t reacted with isobutane in the presence of sulfuric aicd to form alkylate (9). Third, the reaction products from all three n-butenes alkylated in identical manners as will be discussed later (9). Fourth, McCauley (14) has shown that butyl fluorides can be formed and are quite stable at low temperatures such as used here he had contacted HF with n-butenes. 

At least with sulfuric add, key intermediates transfer from and across the interfaces. For example, sec-butyl acid sulfate transfers into the add phase, whereas di -sec-butyl sulfate transfers into and dissolves mainly in the hydrocarbon phase. No information is available on the fraction of isoalkyl fluorides in the two phases. This fraction likely depends on the amount of conjunct polymers in the HF phase. 

We found that the toxicity and myotic activity of di-i opropyl phosphorofluoridate (XI) were far greater than that of di-n propyl phosphorofluoridate. In Report no. 6 on fluoro-phosphonates to the Ministry of Supply we described the preparation of di-aec. butyl phosphorofluoridate (XII) by the hydrogen phosphite method (p. 6). The compound was found to be very toxic and to produce severe myosis in man and ani mala. The symptoms displayed during and after exposure were identical with those produced by di-i opropyl phosphoro-fluoridate. The l.c. 50 for di sec.-butyl phosphorofluoridate for mice for deaths within 2 hr. was 0-6 mg./l., and that for deaths within 48 hr. was 0-54 mg./l. 

A trivial case of macromolecular isomorphism involves the mixing of species differing only in an isotope, for example, as isotactic polypropylene and isotactic polydeuteropropylene (Natta et ai, 1958). More interesting examples can be realized by melting together such polymers as poly(vinyl fluoride) and poly(vinylidene fluoride) (Natta et a/., 1971) or poly(isopropyl vinyl ether) and poly(sec-butyl vinyl ether) (Allegra and Bassi, 1969) that form isomorphic pairs at all relative compositions. 

Typical alkylation reactions are those of propane, isobutane and n-butane by the t-butyl or sec-butyl ion. These systems are somewhat interconvertible by competing hydride transfer and rearrangement of the carbenium ions. The reactions were carried out using alkyl carbenium ion hexafluoroantimonate salts prepared from the corresponding halides and antimony pentafluoride in sulfuryl chloride fluoride solution and treating them in the same solvent with alkanes. The reagents were mixed at — 78 °C, warmed up to — 20 °C and quenched with ice water before analysis. The intermolecular hydride transfer between tertiary and secondary carbenium ions and alkanes is generally much faster than the alkylation reaction. Consequently, the alkylation products are also those derived from the new alkanes and carbenium ions formed in the hydride transfer reaction. 

When re-olefins are used, either isoalkyl sulfates or isoalkyl fluorides are obtained at least to some extent as intermediates. The production of sec-butyl sulfates has been investigated in considerable detail (13,14). These sulfates then decompose releasing primarily 2-butenes, which are thermodynamically preferred as compared with 1-butene. The isobutane/2-butene ratio is very high because of the slow rate of 2-butenes released. The 2-butenes react as they are released forming mainly TMPs (12,17). 

Synthesis. Titanium alkoxy halides are intermediates in the preparation of alkoxides from a titanium tetrahaUde (except the fluoride) and an alcohol or phenol. If TiCl is heated with excess primary alcohol, only two chlorine atoms can be replaced and the product is dialkoxydichlorotitanium alcoholate, (RO)2TiCl2 ROH. The yields are poor, and some alcohols, such as aHyl, ben2yl, and /-butyl alcohols, are converted to chlorides (46). Using excess TiCl at 0°C, the trichloride ROTiCl is obtained nearly quantitatively, even from sec- and / f/-alcohols (47,48). 

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