Phenoxymethylpenicillin sulfoxide benzyl ester (IVb).Phenoxymethylpenicillin benzyl ester was much more resistant to oxidation with sodium periodate. A solution of 4.7 g. (0.0107 mole) of phenoxymethylpenicillin benzyl ester lib was stirred with sodium periodate in dioxane-phosphate buffer for 10 hr. at room temperature, then for 4 days with fresh sodium periodate-dioxane-phosphate buffer, and finally for 2 days at 50°with fresh periodate-dioxane-phosphate buffer. The reaction mixture was worked up as with the benzylpenicillin sulfoxide benzyl ester. Evaporation of the chloroform solution gave an oil which crystallized after 9 days to give 2.95 g. (61%) of crude phenoxymethylpenicillin sulfoxide benzyl ester IVb, m.p. 123-125°. Recrystallization from ethyl acetate-petroleum ether gave 2.75 g. (57%) of crystalline solid, m.p. 124-125°.

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filo Notes Yol. 11 Experimental Section15l- 2,3,.-A mixture of 100 g (0.38 mole) of diphenyl-4-pyridineniethanol, 100 ml of dioxane, and 50.5 g (0.40 mole) of MesSO* was heated on a steam bath for about 30 min, the solvent, was removed under vacuum, and the resulting residue was dissolved in f-PrOH. The pyridinium salt 1 was precipitated by addition of 1.5 vol of petroleum ether (bp 75-90°); 136 g, mp 169-171°. It was dissolved in a mixture of 1 1. of IT20, 2 1. of MeOII, and 50 ml of 50%: aqueous NaOH. The reaction flask was cooled in an ice bath and a solution of 77 g of NaBTL in 400 ml of II2() was added dropwise. Cooling was continued for 2 hr after which time the mixture was heated on a steam bath to allow evaporation of methanol. The product crystallized from the reaction mixture on cooling, was collected, washed (TLO), and recrvstallized from EtOAc to give 95.5 g (85% yield) of 2: mp 179-180.5°(lit.4b mp 179.0-179.8°); Xmax (MeOII) 248 my

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May, 1962PYRIDOXINE ANALOQS 531 at 134-135' and a mixture m.p. waa 131-132' (lit.? 138-139'). The infrared spectra (Nujol mull) for synthetic and isolated products were identical.Isolation of VI1.-This compound was isolated from rabbit urine in low yield by the procedure of Paul, et a2.a Comparison with the photochemically produced product is given below.Photochemical Product of 5-Nitro-2-furaldehyde Diacetate.-Dry 5-nitro-2-furaldehyde diacetate (IX) (100 9.) was irradiated with frequent mixing in flatsided Roux bottles which had been flushed with nitrogen and stoppered. About one hour of midday sunlight caused the white solid to turn green. Irradiation in air resulted in yellowing and decreased the yield. The green crystals were dissolved in 500-600 ml. of warm (about 50') ethanol, then 600 ml. of water and 1500-2000 ml. of ethyl acetate were added. The yellow water-alcohol layer was separated and the brown-red ethyl acetate layer washed once with about 100 ml. of water. The combined aqueous layers were extracted twice with equal volumes of ethyl acetate to remove residual I X yielding an aqueous phase with absorption maxima at 400 and 300 mp. The ratio of absorbances a t 400:300 mp is 2.1:l. l-Is0propylidene-2-acetylhydrazine (1 g.) and 1 ml. of concd. HC1/500 ml. of solution were added. After standing overnight in the refrigerator, the solution waa concentrated in vacuo to yield a brownish-yellow solid with absorption maxima at 415 and 320 mp; recrystallization from water did not give a pure product. VI1 isolated from urine*o yielded upon hydrolysis in dilute HC1 a t 70' a product which absorbed at 400 mp, and which corresponded in Rr in the butano1:etha nol: ", OH solvent with that of the photochemically produced VIII. Both of these compounds had Rr 0.5 and both VI1 compounds had Rr 0.20. Solutions of either, on standing for 0.5 hr. at room temperature with an equal volume of 0.2% 2,4dinitrophenylhydrazine in 2 N BCl, yielded red derivatives with Rr 0.27 and Amax. 462 mr. An infrared spectrum (KBr pellet) of isolated VI1 showed no nitro group absorption and bands at 5.75, 5.95 and 6.9 p .The syntheses of three new analogs of pyridoxine have been described. On biological evaluation in rats, 3-chloro-4,5-bis(hydroxymethyl)-2-methylpyridine hydrochloride (I) was a weak vitamin Be antagonist compared with deoxypyridoxine.