Thioether-esters

R e = alkyl, alkoxy, thioether, ester amino, aryl, halogen etc. 

Therefore, it is possible to convert a variety of primary and secondary alkyl halides to alcohol, ethers, thiols, thioethers, esters, amines, and azides (Following fig.). Alkyl iodides and alkyl chlorides can also be synthesised from other alkyl halides. 

At first glance, the data seem a little inconsistent because the chemiluminescence was measured (at 25°C or 150°C) from samples which had stood at ambient temperature after irradiation in each case. Apparently the irradiation and ambient-temperature storage left the thioether ester essentially unchanged, so that upon heating to 150°C after various storage periods, nearly the full complement of antioxidant became available to retard autoxidation. The resulting chemiluminescence data correlate therefore with aging results at 60°C, at which temperature the thioether ester is an active antioxidant. ... 

The thioether ester (DLTDP) shows a very strong synergistic effect with the phenolic stabilizer at room temperature, and is active alone at 60°C for protection from loss of impact strength of the irradiated polypropylene. 

Racemic 4-acetoxy-3-unsubstituted azetidinone 10 and homochiral (3R,4R)-3-(IR)-hydroxyethyl derivative 11, commercially available intermediates industrially prepared by the so-called CSI route , testify to the importance of this ring formation strategy. By using vinyl acetate as the olefin partner in the chlorosulfonylisocyanate-alkene cycloaddition, in 1974, Clauss et al. [10] laid down the basis of this approach in the field of p-lactam antibiotics. The most recent efforts have been directed to the key intermediate 11 and its synthetic equivalents 12, 13. Starting from methyl 3R-hydroxybutyrate [11], three independent methodologies have been realized, the main difference being the type (ether, thioether, ester) of enolate used. 

Moan and coworkers have reported a series of hematoporphyrin dialkyl ethers 1 (Scheme 2) and observed that the sensitizing efficiency increased with decreasing polarity. Hematoporphyrin diamyl ether was more efficient than HpD and was slightly less effective than Photofrin. Pandey et al. also observed that the di-phytyl ether derivative of hematoporphyrin 2 was nearly as active as Photofrin in vivo. However, the related phytyl ester derivatives 3 and protoporphyrin 4 did not show any photosensitizing activity. A few years later, Woodbum et al. and Reiss and coworkers reported a series of hematoporphyrin derivatives substituted at the 3 and 8 positions (lUPAC nomenclatiue) of the macrocycle with ether, thioether, ester and amino functions 5. Some of these analogues were found to be biologicaly active. 

More highly substituted phenazines include aldehydes, thioethers, ester and amides, which besides being antibiotic exhibit radical scavenging and antitumor activity. 

The presence of sulfur volatiles has now been reported in a wide range of fruits and has been found to correlate well with quality in strawberries (9) and black currant buds (JO). Detailed studies of the volatiles in pineapple (11,12,13) also reported the presence of several thioether esters including methyl (methylthio)acetate, ethyl (mediylthio)acetate, 3-(methylthio)propyl acetate, methyl 3-(methylthio)propanoate, ethyl 3-(methylthio)propanoate and the alcohol, 3-(methylthio)propan-l-ol. The sulfur esters 3-(meAylthio)propyl acetate and ethyl 3-(methylthio)propanoate were also detected in Asian pears (14), and fifteen sulfur volatiles, including 3-(methylthio)hexyl acetate, have recently been reported in yellow passionfruit (15). 

Since the exocyclic sulfur is more reactive in the ambident anion than in A-4-thiazoIine-2-thione. greater nucleophilic reactivity is to be expected. Thus a large variety of thioethers were prepared in good yields starting from alkylhalides (e.g.. Scheme 38 (54, 91, 111, 166-179). lactones (54, 160), aryl halides (54, 152. 180, 181), acyl chlorides (54. 149, 182-184). halothiazoles (54, 185-190), a-haloesters (149. 152. 177. 191-194), cyanuric chloride (151). fV.N-dimethylthiocarbamoyl chloride (151, 152. 195. 196), /3-chloroethyl ester of acrylic acid (197), (3-dimethylaminoethyl chloride (152). l,4-dichloro-2-butyne (152), 1,4-dichloro-2-butene (152), and 2-chloro-propionitrile (152). A general... 

Phthalocyanine sulfonic acids, which can be used as direct cotton dyes (1), are obtained by heating the metal phthalocyanines in oleum. One to four sulfo groups can be introduced in the 4-position by varying concentration, temperature, and reaction time (103). Sulfonyl chlorides, which are important intermediates, can be prepared from chlorosulfonic acid and phthalocyanines (104). The positions of the sulfonyl chloride groups are the same as those of the sulfonic acids (103). Other derivatives, eg, chlormethylphthalocyanines (105—107), / /f-butyl (108—111), amino (112), ethers (109,110,113—116), thioethers (117,118), carboxyl acids (119—122), esters (123), cyanides (112,124—127), and nitrocompounds (126), can be synthesized. 

Related to the crown ethers are compounds, such as hexamethyl-[14]-4,ll-diene (6), which differ by the replacement of one or more of the oxygen atoms by other kinds of donor atoms, particularly N or S. MacrocycHc amine and thioether compounds have been synthesized. Compounds having more than one kind of heteroatom in the ring are called mixed-donor macrocycles. The naturally occurring metaboUtes nonactin [6833-84-7] and monactin [7182-54-9] have both ether and ester groups incorporated in the macrocyclic stmcture. 

A wide variety of /3-lactams are available by these routes because of the range of substituents possible in either the ketene or its equivalent substituted acetic acid derivative. Considerable diversity in imine structure is also possible. In addition to simple Schiff bases, imino esters and thioethers, amidines, cyclic imines and conjugated imines such as cinnamy-lidineaniline have found wide application in the synthesis of functionalized /3-lactams. A-Acylhydrazones can be used, but phenylhydrazones and O-alkyloximes do not give /3-lactams. These /3-lactam forming reactions give both cis and /raMS-azetidin-2-ones some control over stereochemistry can, however, be exercised by choice of reactants and conditions. 

Bonds between carbon and various heteroatoms (e.g. O, N, S, P) which are easily generated synthetically are strategic for disconnection. Specific bonds in this category are ester, amide, imine, thioether, and acetal. 

A great advantage of catalyst 24b compared with other chiral Lewis acids is that it tolerates the presence of ester, amine, and thioether functionalities. Dienes substituted at the 1-position by alkyl, aryl, oxygen, nitrogen, or sulfur all participate effectively in the present asymmetric Diels-Alder reaction, giving adducts in over 90% ee. The reaction of l-acetoxy-3-methylbutadiene and acryloyloxazolidinone catalyzed by copper reagent 24b, affords the cycloadduct in 98% ee. The first total synthesis of ewt-J -tetrahydrocannabinol was achieved using the functionalized cycloadduct obtained [23, 33e] (Scheme 1.39). 

S-Methyl thiourea Chloroformic acid methyl ester 3,4-Diamino-diphenyl-thioether... 

---