[I / \P--At ~i / Ar-P" + 2RSSR ---~ 2At --P I~ \SR \ s / s (1) (2a~ b) ~3a. b) Ar=4-MeOC~H,: R=Et(a), i-Bu(b), The IR spectra of (3a) and(3b) have bands at (v, cm'l): 3075-3070 w, 3010 w (:C-H, Ar), 1594-1590 s, 1500-1497 s (C'-w-" CAr), 698-696 v.s.br (P--S), 535 s, 515-515-510 m (PS2). The IR spectrum of (3b) also has bands at 1388 m, 1370 m /~[(CH3)2C gem]. 31p NMR spectra (10.2 and 162 MHz, from 85% H3PO4): 3P 85 (3a), 82.7 ppm (3b) (in CC14). S,S-Ethyl S'-ethyl(4-methoxyphenyl)phosphonotrithiolothionate (3a) was obtained in 40% yield. The heating element of the molecular distillation apparatus was maintained at 150-160°C (0.02 mm), d42° 1.2738, no 2° 1.6659. PMR spectrum at 60 MHz in CCI 4 with (Me3Si)20 as the internal standard (~5, ppm, J, Hz): c5 t 1.17 t and fi2 1.32 two t (6H, CH3CS, 3JHH = 7.2), 2.45-2.85 m (2H, CCH2SP), 2.85 q (2H, CCH2SS, 3Jnn = 7.2), 3.75 s (3H, CH30), 6.83 d.d (2H, 3,5-H2C6_H_H2, 3JHH = 9.0, 4JpH = 4.5), 7.85 d.d (2H, 2,6-H2C6H2, 3JHH = 9.0, 3JpH = 15.0). Mass spectrum at 100 eV, m/z: [M + H] + 325. Found, %: C 40.52; H 5.58; P 9.75; S 39.96. C1tH17OPS4. Calculated, %: C 40.74; H 5.30; P 9.56; S 39.47%. S,S-Isobutyl S'-isobutyl(4-methoxyphenyl)phosphonotrithiolothionate (3b) was obtained in 30% yield. The heating element of the molecular distillation apparatus was maintained at 170°C (0.02 mm), d42° 1.1223, no 2° 1.6209. PMR spectrum at 60 MHz in CCI 4 with (Me3Si)20 as the internal standard O, ppm, J, Hz): t31 0.98 d and fi2 1.00 d (12H, CH3CC, 3JHr I = 6.5), 1.50-2.17 m (2H, CHCS), 2.52 d (2H, CH2SS, 3JHH = 6.5), 2.86 d.d (2H, CH2SP, 3JHH = 6.5, 3JpH = 14.0), 3.79 s (3H, CH30), 6.84 d.d (2H, 3,5-H2C6_H_H2, 3JHr I = 9.0, 4JpH = 3.0), 7.87 d.d (2H, 2,6-H2C6H 2, 3Jan = 9.0, 3JpH = 14.0). Found, %: C 47.09; H 6.72; P 7.98; S 33.34. C15H25OPS 4. Calculated, %: C 47.36; H 6.64; P 8.15; S 33.44.