Several alternative non-phosgene methods for DPC synthesis have also been proposed. Among them, the transesterification of dimethyl oxalate (DMO) with phenol to diphenyl oxalate (DPO) followed by decarbonylation of DPO to DPC is a promising process.

• 非光气的苯酚和草酸二甲酯（DMO）酯交换合成DPC是以苯酚和DMO酯交换反应合成草酸二苯酯（DPO），DPO再进一步脱羰基反应生成DPC。