How does phenacetin's synthesis chemistry and feedstock linkage to sodium sulfide affect its production cost and supply chain in China?

How does phenacetin's synthesis chemistry and feedstock linkage to sodium sulfide affect its production cost and supply chain in China?
Phenacetin production is chemically straightforward — acetylation of p-phenetidine — but its supply chain ties into sodium sulfide, a commodity chemical used across dye, leather, and paper industries. Sodium sulfide serves as a reducing agent in phenacetin synthesis, and its price volatility directly impacts production costs. Chinese sodium sulfide capacity is concentrated in the northwest, with red and yellow flake grades common; any environmental shutdowns in that sector ripple into phenacetin economics. Additionally, the original Bayer route started from p-nitrophenol, a dye industry byproduct, meaning phenacetin cost is historically linked to dye intermediate availability. Today, Chinese producers benefit from integrated phenol and nitrobenzene chains, keeping raw material costs competitive. However, with phenacetin demand shrinking, producers face margin pressure, making cost optimization through feedstock sourcing critical.