Formaldehyde → HCID 13014656, compound

Participants

Reaction Conditions

Reaction Steps

Pimelic acid monobenzyl ester was prepared according to an adaptation of the method of Hassner et al, Tetrahedron Letters No. 46, 4475 (1970); it boils at 205° C. (1.5 torr). This material was converted to benzyl 6-chloroformylcaproate according to the above methods and 5.25 g of the latter compound was stirred with 0.59 g of paraformaldehyde and several mg of fused zinc chloride and heated to 120° C. in an oil bath. After the paraformaldehyde was consumed (about 11/2 hrs), the mixture was cooled, giving 5.73 g of multi-component product. Purification of 3.85 g of this crude product was achieved on a 180 g (2.9×61 cm) column of Silica Gel 60, prepared in a solvent of toluene/chloroform 9:1. The column was run at the flow rate of 1.8 ml/min. and 20 ml fractions were collected. The column was eluted first with 3 liters of toluene/chloroform 9:1, secondly with 3 liters of a 8.5:1.5 mixture of these solvents and finally with 1 liter of toluene containing 15% of chloroform and 7.5% of ethyl acetate. The various fractions were analyzed and combined where appropriate to produce 1.00 g of an oil identified as benzyl chloromethyl pimelate; ir 1765 and 1735 cm-1 ; pmr δ 7.34, 5.68, 5.11, 2.25-2.50 and 1.1-1.9 ppm.

Provenance & Evidence