抄録
Dibenzoyldisulfide (DBDS) reacted exothermically with phosphorus triamide P (NR2) 3 in benzene to yield a corresponding benzamide.
Although dibenzoylsulfide (DBS) was considered as an intermediate, DBS was not obtained. The yield of the corresponding benzamide decreased with increase of the bulk of the alkyl group on the nitrogen atom of P (NR2) 3.
In the reaction with P (OEt) 3, DBS was obtained in good yield in the reaction of molar ratio 1 : 1. This is in contrast with the case of P (NR2) 3. Excess P (OEt) 3 was allowed to react with DBDS to yield equivalent ethyl benzoate and ethyl thiobenzoate.
In the reaction of DBS with P (NR2) 3, it is considered that the nitrogen atom of P (NR2) 3 attacks the carbon atom of the carbonyl group and then a tervalent phosphorus compound such as acylthiophosphite is formed. In the case of P (OFt) 3, the phosohorus atom is considered to attack the carbon atom of the carbonyl group and to give acylphosphonate and acylthiophosphite.
