Sec.-Octyl hydrogen phthalate

MC.-Octyl alcohol methyl n-hexyl carbinol CH3CH(OH)(CHj)jCH3 = CgH,OH is converted by heating with phthalic anhydride into sec.-octyl hydrogen phthalate ... 

The latter upon decomposition with dilute hydrochloric acid yields laevo sec.-octyl hydrogen phthalate the crystalline brucine salt, when similarly treated, affords the dextro sec.-octyl hydrogen phthalate. These are reerystallised and separately hydrolysed with sodium hydroxide solution to yield pure I- and d-sec.-octyl alcohols ... 

The yield of sec. -octyl hydrogen phthalate from the crude sec.-octyl alcohol used in this preparation was 61-64 per cent. 

The resolution of sec.-octyl alcohol was first described by Pickard and Kenyon. The method employed by these authors differed from the foregoing in the following respects. The brucine salt of sec.-octyl hydrogen phthalate was crystallized several times from acetone until it reached optical purity and was then decom-... 

The inactive sec.-octyl hydrogen phthalate may be recrystallised from light petroleum, b.p. 60-80°, or from glacial acetic acid, and then melts at 55°. 

Introduce 197 g. of anhydrous brucine or 215 g. of the air-dried dihydrate (4) into a warm solution of 139 g. of dl-sec.-octyl hydrogen phthalate in 300 ml. of acetone and warm the mixture under reflux on a water bath until the solution is clear. Upon cooling, the brucine salt (dA, IB) separates as a crystalline solid. Filter this off on a sintered glass funnel, press it well to remove mother liquor, and wash it in the funnel with 125 ml. of acetone. Set the combined filtrate and washings (W) aside. Cover the crystals with acetone and add, slowly and with stirriug, a slight excess (to Congo red) of dilute hydrochloric acid (1 1 by volume about 60 ml.) if the solution becomes turbid before the introduction of... 

Concentrate the combined filtrate and washings (W) to about half the original volume, and pour it into slightly more than the calculated amount of dilute hydrochloric acid (use a mixture of 30 ml. of concentrated hydrochloric acid and 30 ml. of ice-water) then add about 300 ml. of water. Collect the active sec.-octyl hydrogen phthalate (crude L4) as above (5). The weight of the air-dried ester is about half that of the [Pg.507]

The yields from the sec.-octyl hydrogen phthalates are almost quantitative. Notes. 

The sec.-octyl hydrogen phthalate may be prepared in a purer state and with better yields if the reaction is carried out in the presence of pyridine according to the procedure used by Levene and Mikeska, J. Biol. Chem. 75, 594 (1927). 

---