Butane, 2-fluoro-2-methyl

The hydrofluorination of alkenes with anhydrous hydrogen fluoride has been already described extensively in Houben-Weyl, Vol. 5/3, pp 100-101. In the case of ethene, the yield of fluoroethane increases on raising the temperature (90°C, 20-25 atm), however, the procedure should be carried out at lower temperatures with higher alkenes because of their tendency to polymerize thus, 2-fluoropropane is formed in 60-75% yield at 0-45 C. Similar procedures have been described for 2-fluorobutane, 2-fluoro-2-methylpropane and 2-fluoro-2-methyl-butane from but-l-ene, 2-methylpropene and 2-methylbut-2-ene, respectively.63 Cyclohexene reacts at — 78 C with hydrogen fluoride to give fluorocyclohexane (70%) at 100 C polymerization is observed.59,60 Two equivalents of hydrogen fluoride to allene are taken up at — 70 C, to form 2,2-difluoropropane (50%).64... 

Butane 4-Bromo-2-fluoro-2-methyl-3-oxo- ElOa, 615 (Educt)... 

Butane l-Chloro-l-fluoro-3-methyl-2-oxo- EI0b2. 51 (F.duct)... 

Butane 3-Bromo-2-fluoro-2-methyl-ElOb, 3.34 (En + HF/A1F3/N-Br - amine)... 

Butane 4-Acetoxy-2-fluoro-2-methyl-3-nitro- ElOb, 348 (Fn + 02NBF4)... 

Butane 2-(Benzoyloxy-methyl)-l,4-dibenzyloxy-2-fluoro- ElOb,. 92 (OH - F)... 

One study has made use of abzyme stereoselectivity to resolve the four stereoisomers (R,R, S,S, R,S and SJi ) of 4-benzyloxy-3-fluoro-3-methyl-butan-2-ol [84-87] through the antibody-mediated hydrolysis of a dia-stereoisomeric mixture of their phenacetyl esters (Kitazume et al., 1991b). Antibodies were raised separately to each of four phosphonate diastereo-isomers [88-91], corresponding to the four possible transition states for the hydrolysis of the four diastereoisomeric esters (Fig. 25) (Appendix entry 1.12). Each antibody operated on a mixture of equal parts of the four dias-tereoisomers as substrate to give each alcohol in 23% yield, with >97% ee/de, and leaving the three other stereoisomers unchanged. By sequential action of the four antibodies in turn, the mixture of diastereoisomers could effectively be separated completely (Table 4). In a similar vein, Kitazume also resolved the enantiomers of l,l,l-trifluorodecan-2-ol with 98.5% enantiomeric excess (Appendix entry 1.11) (Kitazume et al., 1991a). 

Initial attempts at the direct fluorination of carbonyl compounds such as acetone,72 butane-one,73 and butyric acid74 with elemental fluorine resulted in the formation of complex mixtures, with only low yields of a-monofluorinated carbonyl compounds formed. However, more recently, methyl 3-phenylpyruvate.75,7<1 and other pyruvate derivatives, e.g. I,77 are reported to be selectively monofluorinated with dilute elemental fluorine at — 10"C in moderate yield. The success of this reaction is attributed to the fact that the substrate predominantly exists in the enol form and not the keto form.77 Direct fluorination of acyclic 1,3-dicarbonyl compounds in formic acid or acetonitrile at room temperatures results in the formation of 2-fluoro-1,3-dicarbonyl compounds in good to excellent yield.78,79 Although in these systems the keto form predominates, there are significant concentrations of the enol form which undergoes fluorination (Table 5).78,79 The fluorination of 1,3-dicarbonyl compounds with acetyl hypo-fluorite is only successful when there are significant concentrations of the enol form compounds which have low concentrations of the enol form are successfully fluorinated by preparation of their metal cnolates followed by fluorination with acetyl hypofluorite (see Section 1.1.2.5.).95... 

C5H9F 2-fluoro-trans-2-pentene 66213-88-5 158.72 10.678 2 5309 C5H10Br2 1,2-dibromo-3-methyl butane 10288-13-8 235.21 12.23 0 2... 

C5H9F 4-fluoro-cis-2-pentene 66702-89-4 157.68 8.465 2 5312 C5H10Br2 1,4-dibromo-2-methyl butane 69498-28-8 250.21 15,753 2... 

C5H9F 4-fluoro-trans-2-pentene 66702-90-7 157.68 8.465 2 5313 C5H10Br2 2,2-dibromo-3-methyl butane 62127-60-0 252.63 8.339 2... 

C5H10F2 1,3-difluoro-2-methylbutane 66688-43-5 179.91 7.820 2 5652 C5H11F 1 -fluoro-2-methyl butane 10086-64-3 162.76 8.263 2... 

C5H10F2 1,4-difluoro 2-methyl butane 66688-45-7 194.91 11.343 2 5654 C5H11F 2-fluoro-2-methyl butane 661-53-0 152.15 4.372 2... 

C5H9F 1 -fluoro-3-methyl-2-butene 23425-81-2 15.283 108.796 1,2 5314 C5H10Br2 2,3-dibromo-2 methyl butane 594-51-4 18.671 137.139 1 2... 

The most known designer drugs are carphedone 4-chloro-2,5-dimethoxyphenethylamine (2C-C) i 5-6-(5-chloropyridin-2-yl)-7-oxo-6,7-dihydro-5H-pyrrolo[3,4-b]pyrazin-5-yM-methylpiperazine-l-carboxylate (zopiclone or Z-drug) 4-(N,N-dimethylamino sulfonyl)-7-fluoro-2,l,3-benzoxadiazole (DBD-F) dimethyltryptamine (DMTA) diphenydramine 4-ethyl-2,5-dimethoxyphenethylamine (2C-E) 4-ethylthio-2,5-dimethoxyphenethylamine (2C-T-2) 4-fluoroamphetamine (4-FMP) indan-2-amine 4-iodo-2,5-dimethoxyphenethylamine (2C-I) 1 -(4-iodo-2,5-dimethoxyphenyl)propan-2-amine (DOI) 4-isopropylthio-2,5-dimethyoxyphenethylamine (2C-T-4) meperidine 2-methylamino-l-(3,4-methylenedioxyphenyl)butan-l-one (Bk-MBDB) l-(3,4-methylenedioxybenzyl)piperazine (MDBP) 1 -(3,4-methylenedioxyphenyl)butan-2-amine (BDB) N-methyl-3,4-methylenedioxymethamphetamine (MMDA-2) N-methyl-1 -(3,4-methylenedioxyphenyl)butan-2-amine (HMDMA) N-methyl-l-(3,4-methylenedioxyphenyl)butan-3-amine (HMDMA) methylphenidate 4-methoxymethamphetamine (PMMA) l-(4-methoxyphenyl)piperazine (4-MPP) 2-(6-methyl-2-p-tolylimidazol[l,2-9]pyridine-3-yl)acetamide (zolpidem) normeperidine 4-phenylbutylamine (4-PBA) 3-phenyl-1-peopyTamine (3-PPA) and 2,4,6-trimethoxyamphetamine (TMA-6). 

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