SYNTHESIS AND HYDROLYTIC STABILITY OF SOME NEW PHOSPHONODITHIOITE, PHOSPHONODITHIOATE AND PHOSPHONOTRITHIOATE ESTERS

Abstract

The compounds RP(SCH_{2 5}CH_{2 5}CO_{2 5}CH_{2 5}CH₃)₂ (R = (CH₃)₃ C, C_{6 5}H₅) have been prepared from RPCI₂ and HSCH₂CH₂CO₂CH₂CH₃ and base. The compounds react with hydrogen peroxide and with sulfur to give RP(O)(SCH₂CH₂CO₂CH₂CH₃)₂ and RP(S)(SCH₂CH₂CO₂CH₂CH₃)₂ respectively. The 5-membered ring compound C₆H₅ has been synthesized from C₆H₅PCI₂ and diethyl-2,3-dimercaptosuccinic acid and base. The compound reacts with hydrogen peroxide and with sulfur to give C₆H₅ and C₆H₅ respectively. Reacting C₆H₅PCl₂ with one equivalent of HSCH₂CH₂CO₂CH₂CH₃ and base gives C₆H₅PCI(O)(SCH₂CH₂CO₂CH₂CH₃), which undergoes hydrolysis to give C₆H₅PH(O)(SCH₂CH₂CO₂CH₂CH₃). Except for C₆H₅ and C₆HSPH(O)(SCH₂CH₂CO₂CH₂CH₃), the compounds do not undergo significant hydrolytic cleavage of the P-S bond. The hydrolysis of C₆H₅ likely proceeds via C₆HSPH(O)(SCH(CO₂CH₂CH₃)CH(CO₂CH₂CH₃)SH). The increased hydrolysis rate of C₆H,PH(O)(SCH₂CH₂CO₂CH₂CH₃) is possibly due to hydrogen bonding between water and the PH(O) functionality.

Key Words:

• Phosphonodithioite
• phosphonodithioate
• phosphonotrithioate
• hydrogen bonding
• NMR spectra.