Give-Tan

Cinoxate. 3-(4-Methoxyphenyl)-2-propenoic acid Z-Cthoxyethyl ester p-methoxycinnamic acid 2-ethoxyethyl ester 2-ethoxyethyl p-methoxycinnamate Give-Tan Sun-Dare. C H.,0, moi wt 250.28. C 67.18%, H 7,25%, O 25.57%. Prepn Brit, pat, 856,411 (I960 to Givaudan). 

G is called the loss modulus. It arises from the out-of-phase components of y and T and is associated with viscous energy dissipation, ie, damping. The ratio of G and G gives another measure of damping, the dissipation factor or loss tangent (often just called tan 5), which is the ratio of energy dissipated to energy stored (eq. 16). 

Plots of loss modulus or tan 5 vs temperature for polymers give peaks at energy absorbing transitions, such as the glass transition and low temperature secondary transitions (Fig. 20). Such plots are useful for characterizing polymers and products made from them. 

AH three systems give similar tensile strength, elongation, and hardness properties. Hysteresis (heat buildup) measured by tan 5 shows an advantage for conventional and semi-EV systems and unaged fatigue follows the expected pattern. 

To the cooled reaction mixture, 200 ml. of water is added carefully with stirring. Potassium carbonate is added with continued stirring until the water layer is saturated the mixture is now transferred to a separatory funnel and extracted three times with 60-ml. portions of ether. The combined ether extracts are dried over solid sodium hydroxide and are then transferred to a simple distillation apparatus. Distillation is commenced with a steam bath as source of heat when most of the ether has been removed, the steam bath is replaced by a flame. Distillation is continued until most of the piperidine (b.p. 106°) has been removed. The cooled residue in the distillation flask is recrystallized from petroleum ether (boiling range 30-60°) with the use of charcoal. There is obtained 30.0 g. (71%) of N-/3-naphthyl-piperidine as tan crystals, m.p. 52-56°. An additional recrystallization from the same solvent gives crystals, m.p. 56-58°, with about 10% loss in weight (Note 6). 

Commercial Sodium Acetylide A suspension (30 ml) of sodium acete-lide (20% in exylene) is centrifuged and the solid brown sodium acetylide is taken up in 25 ml of dimethyl sulfoxide. To this is added a solution of 5 g of 5a-hydroxy-6j5-methylandrostane-3-17,dione 3-ethylene ketal in 85 ml of dimethyl sulfoxide. After stirring at room temperature overnight, ice is added and the solution diluted to about 250 ml. The tan precipitate is collected, washed with water and dried yield 4.8 g mp 202-204°. Crystallization from ethyl acetate gives a product of mp 204-206°. 

The reaction of 17 g (0.177 mole) of 2-cycIohexene-l-one under the conditions previously described gives about 29 g of tan solid on cooling. Several recrystallizations may be necessary to remove a small amount of isomer formed. The pure product has mp 138-141°. 

Cyclopropyltriphenylphosphonium Bromide (5). The lactone salt is pyrolyzed by placing it in a round-bottom flask fitted with an adaptor attached to a vacuum source (aspirator is sufficient). The flask is heated (oil bath) to 180-190° for 48 hours. The residue is a virtual quantitative yield of the tan product, which may be crystallized from ethyl acetate giving cream crystals, mp 189-190°. An alternate setup is convenient if a drying pistol (Abderhalden) is available. The compound is placed in the pistol, which is then evacuated. Decalin (bp approx. 187°) is refluxed over the pistol to provide the heating source. The work-up is the same. 

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