Patent GB-963300-A (GB)
Title: Process for the preparation of pentavalent phosphorus esters
IPC: C07F9/113
Filed: 1962-02-12
Abstract: Pentavalent phosphorus esters having the general formula: <FORM:0963300/C1/1> wherein the groups R3 each represent substituted or unsubstituted hydrocarbon groups with the proviso that the groups R3 of two groups R3O may be bound to one another to form a divalent hydrocarbon group, R0 represents halogen, one of the groups represented by R3, or a functional organic group, R1 and R2 are each hydrogen or one of the groups or atoms represented by R0, p is 0, 1 or 2 and p+q=2 are obtained by reacting a phosphorus ester of the general formula (R3O)mP(R3)n wherein m is 1, 2 or 3 and m+n=3 with a carbonyl compound having the general formula: <FORM:0963300/C1/2> wherein hal is halogen and R1, R2 and R0 are as defined above in the presence of a compound having the general formula R4(XH)r wherein X is the group -CO2-, -SO3-, NHSO3, -SO2-, -S- or -O-, r is an integer and R4 is a substituted or unsubstituted hydrocarbon group, with the proviso that the compound R4(XH)r is not methanol, ethanol or n-propanol. In a modification the phosphorus ester (R3O)mP(R3)n is reacted with the carbonyl compound of the above given general formula and the mixture of the cis and trans pentavalent phosphorus esters obtained, or the trans isomer isolated therefrom, is treated with an acidic material.  The groups R3 preferably contain 1 to 10 carbon atoms and preferably at least one of the groups R3O is a C1-C4 alkoxy group.  The group R3 may be aliphatic, cycloaliphatic, aromatic or of mixed structure and may be substituted by chlorine or bromine, nitro groups, amine groups of the formula N(Hq)(R3)p or another group of the formula R3O wherein R3, p and q are as defined above. The phosphorus ester is preferably of the formula (R3O)P wherein each R3 is a C1-C7 alkyl group, or an aryl or aralkyl group of up to 10 carbon atoms, e.g. phenyl or benzyl. When R0 and/or R1 and R2 are halogen, they are preferably Cl or Br and when R0 is a functional organic group it may be an aliphatic oxycarbonyl group e.g. a carboalkoxy or an alkoxy alkylene oxycarbonyl group of up to 10 carbon atoms, an ester group R3O- or an acyloxyalkoxycarbonyl group wherein the acyl group has the general formula R3C(O), or a sulphur analogue thereof, or it may be a group having the general formula -C(O).N(Hq)(R3)p. R0 is preferably a group of the formula -Y-R3, C(Y)YR3 or C(O)N(R3)2 wherein Y is oxygen or sulphur and R3 is as defined above. The reaction is generally carried out at between 0 and 150 DEG C. and an inert diluent may be present and when the compound R4(XH)r is an alcohol it can be employed as solvent. The compound R4(XH)r may be an acidic organic compound, preferably one having an ionisation constant of at least 10-10 and desirably not greater than 10-2. Examples of acid compounds are alkane, hydroxyalkane, and alkoxyalkane mono- and poly-carboxylic acids and cycloalkane, aromatic, alkaryl or aralkyl mono- and poly-carboxylic acids, sulphur acids e.g. sulphonic and sulphinic acids, sulphamic acids and phenols and thiophenols and when aromatic groups are present in the acid they may be substituted by halogen atoms and/or by one or more nitro, cyano, hydroxy, alkoxy or amino groups. The compound R4(XH)r may also be a monohydric or a polyhydric alcohol (other than methanol, ethanol and n-propanol) and it is preferred that no olefinic and particularly no acetylenic unsaturated linkages are present in the alcohol.  The alcohol may contain inert substituents, thus ether-alcohols may be used. Specified alcohols include aliphatic alcohols, cyclo alkanols, aralkyl alcohols, and alicyclic substituted alcohols. The alcohol used may take part in an ester-interchange reaction with the trialkyl phosphite when the latter is used as the phosphorus compound (R3O)3P so that the final product may contain one or two groups derived from the alcohol. In carrying out the reaction it is preferred to mix the compound R4(XH)r with the carbonyl compound and then slowly introduce the phosphorus ester into the stirred mixture. In the modification of the process the acidic material need only be used in catalytic amount and is preferably a protonic acid having a dissociation constant of at least 10-2, e.g. a strong mineral acid such as HCl or H2SO4 or an organic acid, e.g. an alkane sulphonic acid or benzene sulphonic acid or it may be an a protonic Lewis acid, e.g. boron trifluoroide especially as its etherate, an oxyhalide of sulphur, P2O5, SO2 or SO3 or a salt of a metal that can accept a pair of electrons. Other suitable acidic materials are solid materials having an intrinsic acidity of less than 2, e.g. a natural or synthetic clay-type hydrocarbon cracking catalyst e.g. one containing a combination of silica and alumina, or a cation exchange resin completely or partly in the acid form. The cation exchange resin is preferably one of the sulphonic acid type in which the sulphonic acid group is directly attached to an aromatic ring of a hydrocarbon resin structure, e.g. a sulphonated polymer of a polyvinyl aryl compound (e.g. divinyl benzene) or a sulphonated copolymer of such polyvinyl aryl compound with a monovinyl aryl compound e.g. styrene. The isomerisation with the acidic material is preferably conducted at between 40 and 100 DEG C. and a solvent may be present, e.g. a halogenated alkane such as CH2Cl2 or CCl4. Several examples of the first defined process and of the modified process are given. Specifications 738,883 and 772,193 are referred to.