Preparation of α,ω-Diols of Long Carbon Chains and Their Use in Polyurethane Synthesis

Article abstract of DOI:10.1246/bcsj.71.1477

NaH promoted coupling reaction of HO(CH₂)₁O-TBDMS (1, TBDMS=SiMe₂(t-Bu)) and Br(CH₂)₁₂O-TBDMS (2) followed by deprotection of the organosilyl groups affords HO(CH₂)₁₂O(CH₂)₁₂OH (5). 1,12-Dodecanediol reacts with an excess amount of 2 in the presence of NaH to give TBDMS-O(CH₂)₁₂O(CH₂)₁₂O(CH ₂)₁₂O-TBDMS (6) which is turned into HO(CH₂)₁₂O(CH₂)₁₂O(CH ₂)₁₂OH (7) by removal of the protecting groups. Similar 1 : 2 condensation of hydroquinone with 2 and with Br(CH₂)₆O-TBDMS (3) leads to formation of the corresponding α,α-diols, HO(CH₂)₁₂OC₆H₄O(CH₂) ₁₂OH (9) and HO(CH₂)₆OC₆H₄O(CH₂) ₆OH (11), respectively. The four new long α,ω-diols are isolated and characterized by means of IR and NMR spectroscopy as well as elemental analyses. Polyaddition reactions of 5, 7, 9, and 11 to 1,3-bis(isocyanatomethyl)benzene and 1,1′-methylenebis[4-isocyanatobenzene] give the corresponding poly(urethane)s in high yields. The obtained polymers, which were characterized by IR and NMR spectroscopy, have molecular weights over 20000 as determined from gel permeation chromatography using polystyrene standards.