TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preparation (Claimed): Preparation of the pyrimidine carboxylic acid compound comprises protonating neutral pyrimidine carboxylic acid compound with a free Bronsted acid, preferably trifluoromethanoic acid, trifluoroacetic acid, nitric acid, sulfuric acid or hydrochloric acid, quaternizing or deprotonating the mixture using a base, preferably a heterocyclic compound, an amine, a tetraalkylammoniumhydroxide or a phosphine.Preferred Components: The pyrimidine carboxylic acid is converted by protonating a neutral pyrimidine carboxylic acid derivative into the cationic component, or by deprotonating a neutral pyrimidine carboxylic acid derivative into the anionic component. The neutral pyrimidine carboxylic acid derivative is ectoin or hydroxyectoin. The pyrimidine carboxylic acid derivative is of formula (I) or (II).R0 = H or 1-12C-alkyl;R1 = H or 1-4C alkyl, preferably ethyl;R2 = H, OH (both preferred), NH2 or 1-4C-alkyl;R5 = as R2, preferably H;R6 = H (preferred) or 1-8C alkyl;A- = (R9C(O)O)-, (R1fC(O)O)-, (R9SO3)-, (R1fSO3)-, (R9OSO3)-, (R1fOSO3)-, ((R1fSO2)2N)-, ((R9SO2)2N)-, ((R1fC(O))2N)-, ((R9C(O))2N)-, ((R1fSO2)(R1fC(O))N)-, ((R9SO2)(R9C(O))N)-, ((FSO2)3C)-, ((R1fSO2)3C)-, ((R9SO2)3C)-, (CCl3C(O)O)-, ((CN)3C)-, ((CN)2CR9)-, ((R9O(O)C)2CR9)-, (P(R1f)yF6-y)-, (P(C6F5)yF6-y)-, (R92P(O)O)-, (R9P(O)O2)2-, ((R9O)2P(O)O)-, ((R9O)P(O)O2)2-, ((R9O)(R9)P(O)O)-, (R1f2P(O)O)-, (R1fP(O)O2)2-, ((R1f)2P(O))2N-, (BFzR1f4-z)-, (BFz(CN)4-z)-, (B(C6H5)4)-, (B(C6F5)4)-, (B(OR9)4)-, (N(CF3)2)-, (N(CN)2)-, (AlCl4)-, (SiF6)2-, (R9OSO3)-, (HSO4)-, Br-, (SO4)2-, (SCN)-, (NO3)-, (AlCl4)-, (Al2Cl7)-, (SnCl3)-, (CO3)2-, (SbF6)- or (AsF6)-;R1f = perfluorinated 1-20C-alkyl, perfluorinated 2-20C-alkyl with one or more double bonds, perfluorinated, saturated, partially or completely unsaturated 3-7C-cycloalkyl, preferably phenyl, which is optionally substituted by perfluoroalkyl group, where two R1f may be connected by single or double bond, and one or two nonadjacent C of R1f, not alpha - to the heteroatoms, may be replaced by O, C(O), S, S(O), SO2, SO2O, N=, N=N, NH, NR1a, PR1a or P(O)R1a or an endgroup SO2OR1a or C(O)OR1a;R1a = non-fluorinated, partially or perfluorinated 1-6C-alkyl, saturated or partially unsaturated 3-7C-cycloalkyl, optionally substituted phenyl, including C6F5, or optionally substituted heterocycle;R9 = H, 1-20C-alkyl, 2-20C alkenyl with one or more double bonds, saturated, partially or completely unsaturated 3-7C cycloalkyl (preferably phenyl) optionally substituted by alkyl, where two R9 may be connected by single or double bond and/or 1 or 2 non-adjacent C of R9, not alpha - to heteroatoms, may be replaced by O, C(O), S, S(O), SO2, SO2O, N=, N=N, NH, NR1a, PR1a or P(O)R1a, P(O)R1aO, OP(O)R1aO, PR1a2=N, C(O)NH, C(O)NR1a, SO2NH or SO2NR1a;y = 0-6;z = 0-4;K1+ = ammonium (N(R7)4)+, phosphonium (P(R7)4)+, uronium (((R7)2N)-C(=OR8)(N(R7)2))+, thiouronium (((R7)2N)-C(=SR8)(N(R7)2))+, guanidinium (C((N(R7)2)3)+, sulfonium (S(R7)3)+ or heterocyclic cation (HetN)+, preferably 1,3-dialkylimidazolium, ((HO3S)(CH2)n(NC5H5))+, (N(CnH2n+1)3(CH2C6H5))+ or (NH(CnH2n+1)2((CH2)nOH))+;R7, R8 = H, provided that, in the case of ((R7)4N)+, at most 2 R7 = H and H is excluded for R8, OR1a or NR1a2, provided that in case of the ((R7)4N)+, maximum 1 R7 is OR1a, NR1a2 and OR1a or NR1a2 in case of (((R7)2N)-C(=OR8)(N(R7)2))+ or (((R7)2N)-C(=SR8)(N(R7)2))+, is excluded, CN, provided that, CN in case of (N(R7)4)+, (P(R7)4)+, (((R7)2N)-C(=OR8)(N(R7)2))+ or (((R7)2N)-C(=SR8)(N(R7)2))+, is excluded, 1-20C-alkyl, 2-20C-alkenyl with one or more double bonds, 2-20C-alkynyl with one or more triple bonds, saturated, partially or completely unsaturated 3-7C-cycloalkyl, which is optionally substituted by 1-6C-alkyl, where: one or more R7, R8 is optionally, partially or completely substituted by halo, preferably F and/or Cl, or partially optionally substituted by OH, OR1a, CN, C(O)OH, C(O)NR1a2, SO2NR1a2, C(O)X, SO2OH, SO2X, NO2 or (CH2)n-phenyl, and one or two adjacent and non alpha -C atom of R7 may eb replaced by by O, S, S(O), SO2, SO2O, C(O), C(O)O, N+R1a2, P(O)R1aO, C(O)NR1a, SO2NR1a, OP(O)R1aO, P(O)(NR1a2)NR1a, PR1a2=N or P(O)R1a;n = 1-4, preferably 1-3;X = halo;HetN+ = imidazolium group of formula (a), 1H-pyrazolium group of formula (b), 3H-pyrazolium group of formula (c), 4H-pyrazolium group of formula (d), 1-pyrazolinium group of formula (e), 2-pyrazolinium group of formula (f), 3-pyrazolinium group of formula (g), 2,3-dihydroimidazolinium group of formula (h), 4,5-dihydroimidazolinium group of formula (i), 2,5-dihydro-imidazolinium group of formula (j), pyrrolidinium group of formula (k), 1,2,4-triazolium group of formula (l), 1,2,3-triazolium group of formula (m), pyridinium group of formula (n), pyridazinium group of formula (o), pyrimidinium group of formula (p), piperidinium group of formula (q), morpholinium group of formula (r), pyrazinium group of formula (s), thiazolium group of formula (t), oxazolium group of formula (u), indolium group of formula (v), quinolinium group of formula (w), isoquinolinium group of formula (x), quinoxalinium group of formula (y) or indolinium group of formula (z); andR1aa, R2a, R3a, R4a = H, CN, OR1a, NR1a2, P(O)(OR1a)2, P(O)(NR1a2))2, C(O)R1a, COOR1a, 1-20C alkyl, 2-20C alkyl with one or more double bonds, 2-20C alkyl with one or more triple bonds, saturated, partially or completely unsaturated 3-7C cycloalkyl optionally substituted by 1-6C-alkyl, saturated, partially or completely unsaturated heteroaryl, heteroaryl-1-6C-alkyl or aryl-1-6C-alkyl; orR1aa+R2a+R3a+R4a = ring, where one or more R1aa-R4a is optionally, partially or completely substituted by halo, preferably F and/or Cl, OH, OR1a, CN, C(O)OH, C(O)NR1a2, SO2NR1a2, C(O)X, SO2OH, SO2X, NO2 or (CH2)n-phenyl, non-simultaneous R1aa-R4a is optionally, completely substituted by halo and/or one or two non-adjacent and non-heteroatom bonded C are optionally replaced by O, S, S(O), SO2, SO2O, C(O), C(O)O, N+R1a2, P(O)R1aO, CONR1a, SO2NR1a, OP(O)R1aO, P(O)NR1a2NR1a, PR1a2=N or P(O)R1a. ACTIVITY - Dermatological; Nootropic; Antiseborrheic; Cytostatic; Antiinflammatory.    MECHANISM OF ACTION - None given.    SPECIFIC COMPOUNDS - 9 Pyrimidine carboxylic acid compounds are disclosed e.g. 6-carboxy-2-methyl-1,4,5,6-tetrahydropyrimidinium-octanoate of formula (Ia), 2-methyl-3,4,5,6-tetrahydropyrimidin-4-carboxylate-benzyl-trimethyl-ammonium, 2-methyl-3,4,5,6-tetrahydropyrimidin-4-carboxylate-2-hydroxyethyl-dimethyl-ammonium, 2-methyl-3,4,5,6-tetrahydropyrimidin-4-carboxylate-1-(3-sulfopropyl)pyridinium and 6-carboxy-2-methyl-1,4,5,6-tetrahydropyrimidinium-hydrogen sulfate.    EXAMPLE - In a 100 ml glass, ectoin (20 g) was dissolved in water (25 ml) and subsequently reacted under stirring with octanoic acid (22.3 ml). The reaction solution was further stirred for an hour and completely concentrated in a water bath at approximately 60 degrees C to obtain 6-carboxy-2-methyl-1,4,5,6-tetrahydropyrimidinium-octanoate.