ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Synthesis of some derivatives of alkaloids. XIV

L. Dúbravková, I. Ježo, P. Šefčovič, and Z. Votický

Slovak Academy of Sciences, Bratislava

Abstract: cf. C.A. 52, 11870e. The synthesis of (±)-calycotomine (I), 1-hydroxymethyl-6,7-di-methoxy-1,2,3,4-tetrahydroisoquinoline, is described. To Na benzylate (from 34.5 g. Na and 700 g. PhCH₂OH) was added 71.5 g. ClCH₂CO₂H in 200 ml. PhCH₂OH, the mixt. heated on a waterbath 30 min., H₂O added, the mixt. extd. with Et₂O, the aq. layer acidified, extd. with Et₂O, and distd. giving 90% benzyloxyacetic acid (II), b11 117°, n22D 1.5270. II (16.6 g.) in 50 ml. Decalin was added to 18.1 g. homoveratrylamine (III) in 50 ml. Decalin. After standing 30 min. the mixt. was distd. slowly until the b.p. of Decalin was reached, then in vacuo to remove the remaining Decalin, and the product recrystd. from H₂O to give 91% N-homoveratrylbenzyloxyacetamide (IV), m. 68-9°. IV (32.9 g.) in 250 ml. PhMe and 50 g. POCl₃ was refluxed 1-2 hrs., excess POCl₃ removed in vacuo, the residue dissolved in H₂O, decolorized with C, evapd. to dryness in vacuo, the product redissolved in H₂O, made alk. with 40% NaOH, extd. with Et₂O, dried over K₂CO₃, and the Et₂O removed giving 35% O-benzyldehydrocalycotomine (V); HCl salt, m. 93°; picrate, m. 146°; H₂PtCl₆ salt, m. 174°. V H₂PtCl₆ salt (15.2 g.) in 300 ml. H₂O and 1 ml. concd. HCl was hydrogenated over 0.1 g. Pd-C, the catalyst filtered off, the residue evapd. to dryness, dissolved in H₂O, made alk. with 40% NaOH, extd. with Et₂O, dried, and the Et₂O removed giving 70% O-benzlcalycotomine (VI), m. 32-3°; HCl salt, m. 208-9°; H₂PtCl₆ salt, m. 191-2°. VI.HCl (7 g.) was boiled with 120 ml. 1:1 HCl 2 hrs., the soln. evapd. to dryness in vacuo, the residue dissolved in H₂O, made alk. with 40% NaOH, the product filtered off, and recrystd. from C₆H₆-petr. ether to give a nearly quant. yield of I, m. 135-6° λ 240 (log ε 3.49) and 290 mμ (log ε 3.65); HCl salt, m. 192°; HClO₄ salt, m. 174°; N-Me deriv. HCl salt, m. 221-3° (picrate, m. 162-3°; H₂PtCl₆ salt, m. 172-3°).

Full paper in Portable Document Format: 128a459.pdf (in Slovak)

Chemical Papers 12 (8) 459–463 (1958)