1,1,3,3-Tetramethylguanidine → Triphenylphosphine Oxide

Participants

Reaction Conditions

Reaction Steps

The crystals of (1,2-diethoxy-2-oxoethyl)(triphenyl)phosphonium chloride in the reactor were dissolved in CH2Cl2 (290 L) followed by the addition of 4-benzyloxybenzaldehyde (44.2 kg, 208 mol, yield is based on this chemical). To this solution tetramethylguanidine (25.4 kg, 220 mol) was added in 1 hour. The solution was then stirred for 20 hours at 20° C. CH2Cl2 (200 L) was distilled off and at an Ti of 30° C. replaced TBME (280 l). The crystals of TPPO formed were filtered off at 20° C. and the mother-liquor was concentrated until a new precipitate was formed. The TPPO was filtered off again and the mother-liquor was concentrated until no more solvents distilled. 2-Propanol (260 L) and seeding crystals (ethyl 3-[4-(benzyloxy)phenyl]-2-ethoxy-2-propenoate) (50 g) were added before cooling to 0° C. The resulting suspension was filtered and the isolated material dried at 40° C./160 mbar. The overall yield was 44.5 kg, 65% (GLC: 99% area).

Provenance & Evidence