Silane, chloromethyl-trimethoxy- → Methyl formate

Participants

Reaction Conditions

Reaction Steps

A mixture of sodium formate (53.6 g, 788 mmol) and high boiler solvent dimethylpropyleneurea (DMPU, 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone) (400 mL) was admixed with 100 mL of toluene. To dry the mixture, the toluene was distilled off (47 mbar (head), 26-29° C. (head), 68-90° C. (pot)) and then the vacuum was tightened until only DMPU passed over (1.2 mbar (head), 89° C. (head), 110° C. (pot); about 10 g of DMPU distillate). The remaining mixture was cooled down to 100° C., and (chloromethyl)trimethoxysilane (128 g, 750 mmol) was metered in over 5 minutes, and the resulting mixture was stirred at 100° C. for 30 minutes and at 115° C. for a further 2.5 hours. A reaction check showed complete conversion of the (chloromethyl)trimethoxysilane, and also the desired product (formoxymethyl)trimethoxysilane and the by-products methyl formate, tetramethoxysilane and siloxanes of the silanes formed. The product was distilled at 100° C. temperature (pot) by gradually tightening the vacuum from 15 mbar to 3 mbar (boiling point 59-91° C. (head)). The distillate obtained contained 66.9 g of (formoxymethyl)trimethoxysilane (purity 73.6% (GC area %)); the distillate contained, based on purity, 61.7 g (342 mmol, 46% of theory) of (formoxymethyl)-trimethoxysilane. The solvent, sodium chloride and excess sodium formate remained in the residue.

Provenance & Evidence