Butanenitrile, 4-methylthio- → Hydrogen Cyanide

Participants

Reaction Steps

MMP reaction product produced in the processes illustrated in FIGS. 1 to 8 may be used directly for the preparation of 4-(methylthio)butyronitrile without prior distillation for removal of either high boiling or low boiling impurities. This not only saves the capital and operating expense of providing distillation, but also avoids the yield losses inevitably resulting from the formation of additional high boilers in an MMP distillation column. 4-(Methylthio)butyronitrile (HMBN) may be produced by reaction of the NMP product with hydrogen cyanide. In turn, the HMBN can be converted to 2-hydroxy-4-methylthiobutanoic acid (HMBA) by hydrolysis with sulfuric or other mineral acid. Without distillation or other refining of either the MMP or the HMBN, the HMBN may be converted to HMBA which is suitable for use as an animal feed supplement serving as a source of methionine. MMP produced by the process of the invention may be converted to HMBN as described above, and the HMBN advantageously converted to HMBA by either the process described in guest et al. U.S. Pat. No. 4,524,077 or the process of Hernandez U.S. Pat. No. 4,912,257. In the process of the Ruest patent, HMBN is hydrolyzed in sulfuric acid, the HMBA product extracted from the hydrolyzate using a substantially water-immiscible solvent, and the extract steam distilled to produce an 85 to 90% by weight aqueous solution of HMBA. In the process of the Hernandez patent, the hydrolyzate is neutralized with ammonia, causing it to separate into two phases, the organic phase being evaporated to produce an 85 to 90% aqueous solution of HMBA.

Provenance & Evidence