hydrogen chloride, and rccq-stallizing the precipitated salt from ethanol.10-Acetyl-17,18-dimethoxy-1j,16,17,18,19,20-hexadehydroyohimbane (XXX).-.4 solution of 5.2 g. of 6-acetvl-l-(3,4-diiriethos~l)enzy1)-1,2,3,4-tetrahydro-~-carboline hydrochloride in 75 n i l . i i f 37:; formaldehydeand 130 ml. of acetic acid WYHS heated 011 a ste:im bath for 1 hr., treated with 100 rnl. of water, and m d e I m i r in the cold with 20: ; sodium hydroxide solution. The precipitated prodiic.t was filtered, dissolved in acetonitrile, :mi p:tssed through :i 25-g. Florid column. Combined eluate and xashings were evaporated in z'acuo anti the residue v-as recryst,zllized fr(irii :icetonitrile, yield 50r:, m.p. 216-223' dec.
Investigations in Heterocycles. X's-. Methylphenidate : -i l'ersatile
Intermediate in the Synthesis of Bicyclic Heterocycles with a Bridgehead Nitrogen A tomMethyl a-phenyl-2-piperidinearetate (methylphenidate') has been sho~vn t u be :i useful iriteriiiediate in the. synthesis of a variety of compounds related to hexahydro-lH-p2-rido[l~~cl pyrimidinc-l,3-(2H)dione. In addition, this intermediate has been utilized in the synthesis of the novel bicyclo heterocycles Iiesahydropyrazolo-[ l15a]p)-ridin-2-( 1H)one and 4,5,6,7-tetrahydropymzolo[ 1,3a] pyridin-24 1H)c me.
The facile rearrangement of 4-hydroxyquinoline and its derivatives in the presence of excess hydrazine hydrate gives rise to 5( o-aminophenyl )pyrazoles. These compounds in turn serve as intermediates in the synthesis of some new heterocycles, pyrazolo [ 1,5-c] quinazolines. The chemical and spectral properties of these substances are discussed.
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