Dialkyl mixed

Replacement of Boron by Sulfur and Selenium. Trialkylboranes are cleaved by dialkyl- and diaryldisulfides in an air-catalyzed radical reaction producing mixed thioethers (259). 

PhenylPhosphorodithioate Esters, These differ from the widely used 0,0-dialkyl esters, by having mixed O-alkyl, Talkyl groups. 

Mixed mono- and dialkyl are used as catalysts for resin curing and as intermediates for fire retardants, oil additives, antistatic agents (qv), and extraction solvents. An equimolar mixture of mono- and dialkyl acid phosphates are formed at a 1 6 mole ratio of oxide to alcohol. 

Mixed esteis aie synthesized by the leaction of one alkyl chloiosulfate with a diffeient sodium alkoxide oi a diffeient dialkyl sulfite as follows (92) ... 

Diorgano Sulfites. Symmetrical or mixed dialkyl sulfites ate prepared by the stepwise reaction of thionyl chloride either with two molecules of an alcohol or with stoichiometric quantities of two alcohols in pyridine (105). 

Formation of Sulfides. Thiols react readily with alkenes under the same types of conditions used to manufacture thiols. In this way, dialkyl sulfides and mixed alkyl sulfides can be produced. Sulfides are a principal by-product of thiol production. Mixed sulfides can be formed by the reaction of the thiol using a suitable starting material, as shown in equations 21, 22, and 23. Vinyl sulfides can be produced by the reaction of alkynes with thiols (38). 

The total yield of sulfinic acid from the mixed sulfoxides is higher than that from diphenyl sulfoxides (31%) but lower than that from the corresponding dialkyl sulfoxides, and accounts for about 45% of the OH radicals (Table 1). 

Grignard reactions have been used in the preparation of l-(dialkyl-phosphinyl)- ,3-dienes, e.g. (11), which are intermediates in the synthesis of antiflame polymers. Double-resonance n.m.r. techniques have been applied to the study of the reactions between thiophosphoryl halides and Grignard reagents. For example, the reaction between methylmag-nesium iodide and t-butyldibromophosphine sulphide gave the mixed... 

The preparation of phosphate esters has been reviewed and full details have appeared of the use of 2-chloromethyl-4-nitrophenyl esters (reported last year) in the synthesis of monoesters and mixed dialkyl esters of phosphoric acid. 

In Formula 33 is pictured a completely mixed ester of a thiophosphate in which all groups are different. The thiophosphoryl chloride method was used for preparing such compounds. It was of interest to see whether or not other compounds could be prepared by the condensation of a dialkyl chlorothiophosphate with a phenol to give products such as shown in Formulas 34 to 36. 

Me(Ph)SiCl2 reacts with dimethyl phosphonate in a 1 1-mixture at 100°C to the O.O-disilylated phosphonate. In contrast to this observation the O-alkyl O-silyl phosphonate is formed solely by reaction of both compounds in acetonitrile at 80°C (line 7,8). An excess of the corresponding phosphonate as polar solvent leads to the mixed ester 2 only. The excess of the dialkyl phosphonate is removed from the mixture by vacuum distillation (line 9). 

Steinberg, G.M., Reactions of dialkyl phosphites — synthesis of dialkyl chlo-rophosphates, tetraalkyl pyrophosphates, and mixed orthophosphate esters, /. Org. Chem., 15, 673, 1950. 

Two reports are available on the rearrangement of mixed vinyl phosphite esters to produce phosphonate diesters in moderate yield.94 95 In both instances, the vinyl phosphite esters were prepared by reaction of the dialkyl phosphorous chloride with highly enolized carbonyl compounds. The mixed ester products undergo thermal rearrangement to the phosphonate diesters (Figure 6.25). 

Following the reports of sulfur appended porphyrazines, Fitzgerald et al. (28) reported a facile synthesis of alkyl appended porphyrazines in 1991, preparing the dialkyl dinitrile precursors from alkynes via a Rosenmund von Braun reaction. Later, these types of dinitriles were used in mixed cyclizations to prepare porphyrazines with three dipropyl substituents (6,29). An intriguing extension was the... 

Incorporation of the (.S )-2-mcthyloctoxy group afforded optically active polymers with preferential helical screw sense (see Section 3.11.6.1). The observed helicity was corroborated by force field calculations, which indicated similar helical conformations for both dialkoxy- and dialkyl-substituted polymers. Based on their similar conformational properties, it was suggested that the origin of the spectral red shift was electronic, due to a a-n mixing interaction, as for polymers 76 above, rather than conformational. 

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