Propylene Glycol → 2,2,4,7,7-Pentamethyl-3,6-dioxa-2,7-disilaoctane

1,2-Propanediol (58.8 g, 0.77 mol) was placed in a 500 mL 3-necked RB flask and treated with 0.2 mL trimethylsilyl chloride. A small volume of HMDS (ca. 10 mL) was added, and an exothermic reaction took place as the mixture became homogeneous. The remainder of the HMDS (170 mL) was added at a controlled rate (ca. 3-5 mL/min), maintaining the reaction temperature at ca. 50°-70° C. Heating was continued at 100° C. (1.5 h), 120° C. (1.0 h),and 140° C. (2.5 h). GC analysis (method 1) revealed excess HMDS and one product. Distillation provided 147 g of colorless oil, bp 70°-72° C./10 mm. 1H NMR (CDCl3): 3.83 (m, 1H), 3.50 and 3.38 (AB pattern with additional coupling, 2H), 1.15 (d, J=7 Hz, 3H), 0.15 (partially resolved singlets, 18H).

1. customan exothermic reaction
2. temperaturemaintaining the reaction temperature at ca. 50°-70° C
3. temperatureHeating
4. customwas continued at 100° C.
5. custom(1.5 h), 120° C. (1.0 h),and 140° C. (2.5 h)
6. distillationDistillation

ORD-Eintrag

ord-d1fe7d3fa2ed4eb4bae78796dd4fc1c8

Quelldatensatz

uspto-grants-1993_09

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US05243025