Abstract
An efficient and mild oxidative desulfurization procedure using o -iodoxybenzoic acid has been developed
for the synthesis of carbodiimides starting from easily synthesizable
1,3-disubstituted thioureas.
Key words
o -iodoxybenzoic acid - oxidation - desulfurization - thiourea - carbodiimide
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15
Typical Procedure
Preparation of 1,3-Diphenyl Carbodiimide 2a
3 N
(0.6 mL, 4.38 mmol) in dry CH2 Cl2 (10 mL)
at 0 ˚C was added 1,3-diphenylthiourea (0.5 g, 2.19 mmol)
portionwise over a period of 5 min. After completion of reaction,
as indicated by TLC, reaction mixture was concentrated under vacuum, and
the residue was extracted with hexane (2 × 15
mL). Pure product was isolated after evaporation of the hexane extract followed
by column chromatography (SiO2 , 60-120 mesh, eluent:
hexane). Yield 0.38 g (90%), oily liquid. ¹ H
NMR (300 MHz, CDCl3 ): δ = 7.20
(m, 6 H), 7.31 (m, 4 H). ¹³ C NMR (75
MHz, CDCl3 ): δ = 124, 125.2, 129.2,
136.2, 138.4. IR (KBr): 2140, 2110 cm-¹ .
All synthesized compounds are known compounds. Characterization
data are provided as Supporting Information.
