Patent GB-784225-A (GB)
Title: Acetals of substituted acrylamides
IPC: C07C233/16
Filed: 1954-10-22
Abstract: Acetals of the formula: <FORM:0784225/IV (a)/1> wherein R is a (C1-C3) alkyl group, phenyl or cyclohexyl, R1 and R11 are the same or different and represent hydrogen or (C1-C3) alkyl groups, <FORM:0784225/IV (a)/2> represents the residue of a (C1-C7) aldehyde or of a (C3-C7) ketone, m is 0 or an integer of 1 to 4, and n is 0 or 1, may be polymerized or copolymerized with other ethylenically unsaturated compounds and, if desired, the resulting products may be hydrolysed to convert the acetal groups into hydroxy groups.  The group <FORM:0784225/IV (a)/3> may suitably be derived from acetone, butanone, pentanone, cyclohexanone, formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, isobutyraldehyde, and benzaldehyde. Specified acetal monomers are 4-N-methacrylamidomethyl - 2 : 2 - dimethyl - 1 : 3 - dioxolan, 4 - N-acrylamidomethyl - 2 : 2 - dimethyl - 1 : 3 - di-oxolan, 5 - N - methacrylamido - 2 : 2 : 5 - trimethyl - 1 : 3 - dioxan, 5 - N - acrylamido-2 : 2 : 5 - trimethyl - 1 : 3 - dioxan and 4 - (N-41 - methacrylamidobutyl) - 2 : 2 - dimethyl-1 : 3 - dioxolan.  Specification 625,840, [Group IV (b)], is referred to.ALSO:The invention comprises (1) acetals of the formula <FORM:0784225/IV (a)/1> wherein R is a (C1-C3) alkyl group, phenyl or cyclohexyl, R1 and R11 are the same or different and represent hydrogen or (C1-C3) alkyl groups <FORM:0784225/IV (a)/2> represents the residue of a (C1-C7) aldehyde or of a (C3-C7) ketone, m is 0 or an integer of 1 to 4, and n is 0 or 1; (2) the preparation of compounds of the above formula wherein R may also represent hydrogen, which comprises reacting at a temperature of -20 DEG  to +50 DEG  C. an acid halide of the formula <FORM:0784225/IV (a)/3> wherein "Hal" is a halogen atom, or, alternatively, an acid anhydride of the formula <FORM:0784225/IV (a)/4> with a compound of the formula <FORM:0784225/IV (a)/5> in the presence of an aqueous solution of a base and at least one addition-polymerization inhibitor.  The group <FORM:0784225/IV (a)/6> may suitably be derived from acetone, butanone, pentanone, cyclohexanone, formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, isobutyraldehyde, and benzaldehyde. The amidation is preferably carried out in the presence of a water-immiscible organic solvent.  Specified bases are pyridine, and sodium, potassium, strontium and barium hydroxides.  Preferably, a mixture of an inhibitor which is soluble in the organic solvent employed (e.g. phenthiazine) and an inhibitor which is soluble and effective in the aqueous base (e.g. picric acid) is used. Metadinitrobenzene is also specified as a polymerization inhibitor. The products of the first general formula above may be subjected to acid hydrolysis to form dihydroxy compounds of the formula <FORM:0784225/IV (a)/7> The examples describe the preparation of 4-N-methacrylamidomethyl - 2 : 2 - dimethyl - 1 : 3 - dioxolan, 4 - N - acrylamidomethyl - 2 : 2 - dimethyl - 1 : 3 - dioxolan, 5 - N - methacrylamido-2 : 2 : 5 - trimethyl - 1 : 3 - dioxan, 5 - N - acrylamido - 2 : 2 : 5 - trimethyl - 1 : 3 - dioxan and 4 - (N - 41 - methacrylamidobutyl) - 2 : 2 - dimethyl - 1 : 3 - dioxolan. The Specification describes the hydrolysis of the above compounds to produce N-2 : 3-dihydroxypropylmethacrylamide, N - 2 : 3 - dihydroxypropylacrylamide, N - 1 : 3 - dihydroxy - 2 - methyl - isopropylmethacrylamide, N - 1 : 3 - dihydroxy-2-methyl-isopropylacrylamide and N-5 : 6-dihydroxyhexyl-methacrylamide respectively.  5 - Amino - 2 : 2 : 5 - trimethyl - 1 : 3 - dioxan is prepared by hydrogenation of 5-nitro-2 : 2 : 5-trimethyl-1 : 3-dioxan with Raney nickel in presence of methanol and triethylamine.  5 - Nitro - 2 : 2 : 5 - trimethyl - 1 : 3 - dioxan is prepared by refluxing 2-methyl-2-nitropropane-1 : 3-diol with acetone in presence of paratoluenesulphonic acid.  4 - (41 - Aminobutyl) - 2 : 2 - dimethyl - 1 : 3 - dioxolan is prepared by reacting 4-(41-hydroxybutyl)-2 : 2-dimethyl-1 : 3-dioxolan with benzenesulphonyl chloride and reacting the resulting sulphonic ester with anhydrous liquid ammonia is a sealed tube at room temperature.  Specification 625,840 is referred to.