Abstract

Nitro alcohols are obtained from nitroparaffins by reaction with aldehydes in the presence of an alkaline catalyst. Only 2-nitro-1-butanol, 2-ethyl-2-nitro-1,3-propanediol, 2-methyl-2-nitro-1-propanol, 2-methyl-2-nitro-1,3-propanediol, and 2-hydroxymethyl-2-nitro-1,3-propanediol, the five nitro alcohols produced with formaldehyde, are manufactured in commercial quantities. All these nitro alcohols except nitrobutanol are crystalline solids when pure, are highly soluble in water, and are only moderately toxic by ingestion.

The principal use of the nitro alcohols is as intermediates for the synthesis of amino alcohols by hydrogenation. The nitro alcohols also are a convenient starting material for the synthesis of diamines by a two-step process involving the formation of a nitro amine by reaction of the hydroxyl group with a primary amine followed by hydrogenation.

2-Methyl-2-nitro-1-propanol finds commercial use to promote adhesion of rubber to tire cord in radial tires. It also can serve as a source of formaldehyde in polymer cross-linking. 2-Hydroxymethyl-2-nitro-1,3-propanediol is a registered biocide useful for control of bacteria in such end uses as metalworking fluids and cooling tower water. This compound also finds acceptance in chemical toilets as an odor control agent.