Bis methiodides

Paravallaridine (1) has been utilised as the starting point for the preparation of a number of steroidal quaternary ammonium salts which are exemplified by the bis-methiodides (2a) to (2d). These... 

Irradiation of /m -2-styrylpyridine produces the m-isomer. trans-2 Styrylpyridine hydrochloride, irradiated in water, gives not only its cis isomer but also a dimer hydrochloride. Irradiation of /m -2-styrylpyridine methiodide in benzene suspension yields the bis-methiodide of a dimer, whereas in water it gives the rw-isomer and subsequently the dimer. re y-2-Styrylpyridine methiodide heated at its melting point produces the trans methiodide. Two stereoisomers of the dimer are known ... 

Well-crystallized methiodides serve to characterize nitrogen compounds, for example, in the case of hydrogenated parent 2 and its derivatives 14a and b, which give salts 352a-c (Scheme 80) (59AP143). Dihydrodesoxyastrocasine (9c) forms bis-quaternary salt 353c (65TL1761). 

Ultraviolet irradiation of the methiodide or hydrochloride of 2-styryl-pyridine (XCIII) in the solid state results in transformation of the trans-isomers to the corresponding dimers (XCVa, b) on the other hand irradiation in benzene solution gives both isomerization and dimerization.309 Dimer (XCVa) was produced in low yield on irradiation of XCIII in the powdered form in the presence of air.308 This is in contrast to the reported stability of XCIII toward photodimerization.109 Similar dimerizations have been reported in the case of 2,4-dichloro-3-cyano-6-styrylpyridine,164 2-styrylquinaldine (XCV) and frans-4,4 -diguanyl-stilbene bis(2-hydroxyethane sulfonate) (stilbamidine) (XCIV).82,83... 

Naphthyridine gave only its 6-methiodide (10) (Mel, AcMe, reflux, 12 h >85% 1214 kinetics961) or its l,6-bis(methofluorosulfonate) (11) (neat FSOaMe, exothermic 90%).1061 Other such quaternary salts have been prepared1002 and their physical chemistry examined.993 1002... 

Bis-diacetylmorphol is obtained when the dimolecular alkaloid pseudomorphine methiodide is heated with acetic anhydride, sodium acetate, and silver acetate at 180° C. for twenty-four hours. It has been allotted the bis-2 2 structure [57], but as the structure of pseudomorphine is by no means certain it may equally well be a bis-l l compound (see Chap. III). It has been hydrolysed and methylated to bis-[3 4-dimethylmorphol] [57]. 

Only a very few 4,4 -bis(3-pyrazolin-5-ones) are known in which the rings are linked directly. These are prepared by methylation of 4,4 -bis(2-pyrazolin-5-ones)807>809 or by treatment of the methiodides of 4-(5-chloropyrazol-4-yl)-3-pyrazolin-5-ones with alkali.991 These compounds are listed in Table XV. 

Reaction of the organophosphide from phosphorus and phenyllithium with propylene oxide, followed by hydrolysis, gave bis(2-hydroxypropyl)-diphenylphosphonium bromide in 19% yield and 2-hydroxypropyldi-phenylphosphine (6). The latter was obtained as the methiodide in 19% yield. Reaction of the complex lithium phenylphosphide with benzaldehyde gave bis(a-hydroxybenzyl)phenylphosphine oxide in 12% yield (6). 

Ketone syntheses. Acyl derivatives that favor the arrestment of Grignard reactions beyond the first round include A-acylpyrazoles, acyl hemiacetals, and acyl tributylphosphonium chlorides (generated in situ from RCOCl and Bu,P). The protocol involving Al-methoxy-Al-methyl carboxamides has been extended to the preparation of a-chloro ketones, a-keto amides, and a-diketones (the last two from the oxalyl diamides). Symmetrical diketones are obtained by the Grignard reaction of bis(benzimidazole) methiodides. Note that an analogous reaction of 1,3-disubstituted benzimidazolium salts furnishes aldehydes. ... 

The 6-bis(ethoxycarbonyl)methylene derivative of 9-ribosylpurine 195 obtained by condensation of 6-thioinosine 1-methiodide 194 with diethyl sodiomalonate underwent a Dimroth rearrangement to afford 3-) -D-ribofuranosyl-IbP 196 derivative on heating in methanolic potassium hydroxide (81H1049). 

When tetrahydroberberine methiodides are heated under reflux with sodium bis-(2-methoxyethoxy)borohydride in dioxan, Stevens rearrangement to spiro-benzylisoquinolines and 8-methyltetrahydroberberines occurs. Thus xylopinine (104) gives the bases (105) and (106). Using deuterium-labelled material, it has been shown that the quasi-axially oriented hydrogens at C-8 and C-14 are independently extracted. In the b C-cw salt series the products are spiro-compounds with retention of configuration at C-8 and inversion at C-14 and... 

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