Carbamates, their production and use as fuels additives

Details Carbamates, their production and use as fuels additives Carbamates, their production and use as fuels additives

1989-01-31

1992-04-07

Howard, Jacqueline V.

Organic compounds -- part of the class 532-570 series

Organic compounds

Carboxylic acid esters

44387, 44329, 560157, C07C12504

Patent

active

051030411

DESCRIPTION:

BRIEF SUMMARY
The present invention relates to novel carbamates, their production and their use as fuels additives.
Carbamates are useful in agrochemicals, resins, plasticisers and monomers. A number of therapeutic applications include use as antipyretics, diuretics and antiseptics. A widely used method for the production of carbamates is the reaction of an alkyl isocyanate with an alcohol. A disadvantage of this method is that alkyl isocyanates are highly toxic materials. Other reported methods for producing carbamates are disclosed in Japan Kokai 77, 14745 wherein NaOMe/MeOH, PhNH.sub.2 and (MeO).sub.2 CO are reacted to produce PhNHCO.sub.2 Me, Japan Kokai 79, 163528 which discloses a similar reaction using NaOMe, piperidine, imidazole, carbonyldiimidazole, N-methylpyrolidone or morpholine, U.S. Pat. No. 4,258,683 wherein aromatic amines are reacted with organic carbonates in the presence of zinc and stannous salts, and U.S. Pat. No. 4,268,684 wherein there is disclosed a similar reaction to that of U.S. Pat. No. 4,268,683 except that cobaltous salts are used instead of zinc and stannous salts.
Carbamates have also been used as additives to fuels.
A specific problem thought to involve deposit formation in the combustion chamber is that of octane requirement increase (generally abbreviated to ORI). The problem of ORI is addressed by U.S. Pat. No. 4,236,020, the solution to the problem according to the aforesaid U.S. Patent being to add to the fuel a poly(oxyalkylene)carbamate soluble in a hydrocarbon fuel boiling in the gasoline range. The carbamates of U.S. Pat. No. 4,236,020 comprise a hydrocarbyloxy-terminated poly(oxyalkylene) chain of at least 5 oxyalkylene units containing 2 to 5 carbon atoms per oxyalkylene unit bonded through an oxycarbonyl group to a nitrogen atom of ethylenediamine. Preferred carbamates are those described by the general formula: ##STR1## in which g is an integer 2 to 5, j is an integer such that the molecular weight of the compound is in the range of about 1,200 to about 5,000, Z is a hydrocarbyl of 1 to 30 carbon atoms and sufficient of the oxyalkylene units in the compounds are other than ethylene to render the compounds soluble in hydrocarbon fuels boiling in the gasoline range. The only method disclosed for preparing the carbamates is the reaction of a suitable capped polyether alcohol with phosgene to form a chloroformate followed by reaction of the chloroformate with ethylene diamine to form the active carbamate. A problem associated with this route to carbamates is the use of phosgene which not only is highly toxic but also can lead to products contaminated with chlorine.
We have now found an improved process for the production of carbamates wherein strong organic bases are used as the catalyst.
Accordingly, in a first aspect, the present invention provides a process for the production of a carbamate having the formula: ##STR2## wherein X and Y are independently either hydrogen, a hydrocarbyl group or a hetero-substituted hydrocarbyl group or the group of formula: ##STR3## wherein Z is either a divalent hydrocarbyl or substituted hydrocarbyl group or a group of the formula: either one of X or Y is the group of formula (II), the other of X or Y is hydrogen, ##STR4## wherein X and Y are independently either hydrogen, a hydrocarbyl group, or a hetero-substituted hydrocarbyl group, with a dihydrocarbyl carbonate having the formula: ##STR5## wherein independently R is as defined above in the presence as catalyst of a strong organic base and in the proportions necessary to produce either a mono-carbamate or a bis-carbamate.
Preferably at least one mole of the compound of formula (IV) per mole of the dihydrocarbyl carbonate of formula (V) is employed.
The compound of formula (IV) may be either ammonia (X=Y=H), a primary amine (either of X or Y=H) or a secondary amine (neither of X or Y=H). The amine may suitably be either a monoamine or a polyamine. X and Y may be independently either a hydrocarbyl group of a hetero-substituted hydrocarbyl group. Suitably the hydrocarbyl group may be an alip

REFERENCES:
patent: 4236020 (1980-11-01), Lewis et al.
patent: 4268683 (1981-05-01), Gurgiolo
patent: 4268684 (1981-05-01), Gurgiolo
patent: 4537986 (1985-08-01), Reissenweber et al.
patent: 4659845 (1987-04-01), Rivetti et al.
patent: 4725680 (1988-02-01), Barcelo et al.

Affiliated with

Also associated with

Rating

Carbamates, their production and use as fuels additives does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Carbamates, their production and use as fuels additives, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Carbamates, their production and use as fuels additives will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1896694