Tertiary Butyl Acetate Research Articles

Alkoxides of Vanadium. II. Synthesis of Trialkyl Orthovanadates by Transesterification Reaction

AbstractNormal, secondary and tertiary butyl orthovanadates have been prepared in almost quantitative yields conveniently by the transesterification reaction between ethyl orthovanadate and corresponding organic esters. It has been revealed that the reaction with tertiary butyl acetate is rather slow in contrast with zirconium alkoxides in which it is found to be more facile.

REACTIONS OF (i) ALUMINUM TERTIARY BUTOXIDE WITH ACETYL CHLORIDE AND (ii) ALUMINUM CHLORIDE WITH TERTIARY BUTYL ACETATE

The reactions between aluminum tertiary butoxide and acetyl chloride have been studied. The addition of 1 mole of acetyl chloride to aluminum tertiary butoxide forms monochloride ditertiary butoxide, which, with another mole of acetyl chloride, appears to give the dichloride monotertiary butoxide derivatives. Further, these products appear to react with tertiary butyl acetate formed in the reaction itself, giving acetate derivatives. The above is confirmed by a detailed study of the reactions between aluminum chloride and tertiary butyl acetate, which have been found to result in the acetate derivatives. A plausible mechanism has been suggested.

Reaction of silicon tetrachloride with tertiary butyl acetate. A novel synthesis of silicon tetraacetate

Reaction of silicon tetrachloride with tertiary butyl acetate. A novel synthesis of silicon tetraacetate

The intralesional use of triamcinolone acetonide in psoriasis. A double blind study.

The effectiveness of the treatment of psoriatic lesions by the intralesional injections of triamcinolone acetonide has been demonstrated by many investigators. 1-3 In a double blind study of psoriatic patients triamcinolone acetonide by intralesional injection was indeed found to be effective in clearing the lesion of psoriasis. Its efficacy was markedly greater than hydrocortisone or prednisolone tertiary butyl acetate. Material and Method All patients in this study were hospitalized and had no other form of systemic or topical therapy. In order to avoid the possibility of systemic effect the amount of triamcinolone acetonide injected was limited to 0.2 ml. of 1% suspension. The control material was the vehicle alone to which hydrocortisone acetate was added to make a 0.4% suspension to simulate the cloudy appearance of the triamcinolone acetonide suspension. Hydrocortisone acetate in this concentration was found to be totally ineffective in the treatment of psoriatic plaques. The suspensions were

Kinetics and Mechanisms of the Acid-catalysed Hydrolysis of Tertiary Butyl Acetate

The kinetics of the acid-catalysed hydrolysis of tertiary butyl acetate in water, in aqueous acetone, and in aqueous dioxan, over a range of temperature have been studied. The Arrhenius equation is not obeyed. In 40% water-60% acetone the energy of activation varies from 26-29 kcal mole-1 for temperatures 48-97 �C. This is due presumably to simultaneous hydrolyses via the AAL1 and the AAC2 mechanisms. By combination of oxygen-18 tracer results and kinetic results the rate constants for reactions by these mechanisms in water have been separated. The observed percentage of alkyl-oxygen fission in water varies from 85 at 25 �C to 97 at 60 �C. Rate constants for reactions by the AAL1 and the AAC2 mechanisms are expressed by the equations : k (sec-1 l mole-1) = 10l6.l exp (-27500/RT), and k (sec-1 l mole-1) = 107.9 exp (-l73OO/RT),respectively. However, the parameters of the latter equation may contain considerable errors because the extent of reaction by the AAC2 mechanism is small. In water and in 80% water-20% acetone, tertiary butyl acetate undergoes an uncatalysed solvolytic reaction, involving presumably the BAL1 mechanism. The variation of the rate of this reaction with temperature is expressed by the equation, k (sec-1) = 1012.3 exp (-26800/RT).

Technique for extra-articular injection.

This exhibit processes the application of extra-articular injections of prednisolone tertiary butylacetate with or without hexylcaine hydrochloride for tendon, ligament, muscle, and bursal pathology of an acute or chronic nature which has been resistant to traditional therapy. It has been found that these injections tended to (1) alleviate muscle spasm, (2) reduce the inflammatory process, (3) decrease the pain, and (4) shorten the course of the disease and the duration of its disability. The only contraindications are acute infections, blood dyscrasias, and malignancies. The rational use of muscle relaxants, analgesics, and various modalities of physical therapy in conjunction with these extra-articular injections have made it possible to institute earlier muscle reeducation and motion. Hence, modality has been decreased and the period of rehabilitation substantially shortened. Dosage The dosage of prednisolone tertiary butylacetate (Hydeltra T. B. A., Merck, Sharpe & Dohme) is shown in the accompanying key. The dose of hexylcaine

Effect of Alterations in Side Chain upon Anti-inflammatory and Liver Glycogen Activities of Hydrocortisone Esters

A number of esters of hydrocortisone and related steroids have been examined for activity in the granuloma inhibition (subcutaneous cotton pellet) test, both after local application of the steroids and after systemic administration. Liver glycogen deposition activity was examined by a one-day oral test in mice, a six-day test in rats, and for duration of action after a single subcutaneous injection. Rates of absorption and activity per mg. of steroid absorbed also were determined. Wide differences in activity were found, depending upon the configuration at C-21. Part of this difference was due to diverse rates of absorption, but there were also differences in activity per mg. of steroid absorbed. It is concluded that ease of hydrolysis of the ester is also a factor in determining potency. The tertiary butyl acetate is particularly effective when locally applied, but systemic activity of this ester is relatively low because of reduced rate of absorption and decreased activity per mg. absorbed. After subcutaneous injection, the free alcohol of hydrocortisone is more rapidly absorbed and gives a more prompt response than any of its esters examined. The 9α-fluoro derivative is more gradually absorbed and gives a more sustained response than does hydrocortisone.